Physics Unit6: Work and Energy - 题库网 (tiku.one)

1#

What is the correct unit of work exmfrk673tj -l kpressed in SI units?

A. $kg m/s^2$

B. $kg m^{2}/s$

C. $kg m^{2}/s^2$

D. $kg^2 m/s^2$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

2#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Can work be done on a system if t f(fei,v: tpes0 m 0di9qmo/t(here is no motion?

A. Yes, if an outside force is provided.

B. Yes, since motion is only relative.

C. No, since a system which is not moving has no energy.

D. No, because of the way work is defined.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

3#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If you push twice as hard qe) w4,f g iktu.v5g3xagainst a stationary brick wall, the amount of work you x. fwtqi4k,3e vgg 5)udo

A. doubles.

B. is cut in half.

C. remains constant but non-zero.

D. remains constant at zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

4#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 50-N object was lifted 2.0 m vertically and is being helf)v g .;q9phsgte g,f:d there. How much work is being done in holding the box in this pofe fpgtg hvqg, 9):.s;sition?

A. more than 100 J

B. 100 J

C. less than 100 J, but more than 0 J

D. 0 J

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

5#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If you walk 5.0 m horizontally forward at a constant velocity carrying a 10 u 3u2uvw6ts)/v mzt 9av ox5vv/jla**-N objesm/)x9 t *utvu5*z /v2vwu 63jao vvalct, the amount of work you do is

A. more than 50 J.

B. equal to 50 J.

C. less than 50 J, but more than 0 J.

D. zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

6#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A container of water is lifted vertic vb orjt7;ye3s kqq) k+0f-w5dally 3.0 m then returned to its original position. If the total weight is 30 N, ho-kk35r)t sy+v 70wqdfeqbj;ow much work was done?

A. $45 \; J$

B. $90 \; J$

C. $180 \; J$

D. No work was done.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

7#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Does the centripetal force acting on an obj 1g5qhwzq1t0 uect do work on the object?

A. Yes, since a force acts and the object moves, and work is force times distance.

B. Yes, since it takes energy to turn an object.

C. No, because the object has constant speed.

D. No, because the force and the displacement of the object are perpendicular.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

8#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

You throw a ball straight up. Compare the0pc4u(hqu5mq4nta6tuva -;g sign of the work done by gravity whilqcqha-t uma6 4 ;4u0gtnv(u5pe the ball goes up with the sign of the work done by gravity while it goes down.

A. Work is + on the way up and + on the way down.

B. Work is + on the way up and - on the way down.

C. Work is - on the way up and + on the way down.

D. Work is - on the way up and - on the way down.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

9#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The area under the curve, on a Force versus posit1 fxpre66 lpk)/; wtnwion (F vs. x) graph, representsl1t/kwnp;x 6)fwe rp6

A. work.

B. kinetic energy.

C. power.

D. potential energy.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

10#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

On a plot of Force v2; ;ljuuz):v7x . r dnp af6c-0zmhtxnersus position (F vs. x), what represents the work done by the 7pd:f na-t zuhxjnrmv6c);2z lx0.u ;force F?

A. the slope of the curve

B. the length of the curve

C. the area under the curve

D. the product of the maximum force times the maximum x

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

11#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity $\frac{1}{2} \; mv^2$ is

A. the kinetic energy of the object.

B. the potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

12#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If the net work done on an object is positive, then the object's kv) w4:1sux.(a fm,;fdgjxogi/(trb kinetic energy

A. decreases.

B. remains the same.

C. increases.

D. is zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

13#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If the net work done on an objf kocf ai*lt+9w14l 14aaloo1ect is negative, then the object's kinetic energy

A. decreases.

B. remains the same.

C. increases.

D. is zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

14#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If the net work done on an object is zero, then the object's k k wclzpui-e9g74 a*y3d*mc8binetic energy

A. decreases.

B. remains the same.

C. increases.

D. is zero.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

15#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A truck weighs twice as much as a car, and is moving at twice the speed of the cpvd.xth6t2okp-2t ezy7 ;hd .ar. Whpth.ddk7 x z2-p v;e2.6hy ottich statement is true about the truck's kinetic energy compared to that of the car?

A. All that can be said is that the truck has more kinetic energy.

B. The truck has twice the kinetic energy of the car.

C. The truck has 4 times the kinetic energy of the car.

D. The truck has 8 times the kinetic energy of the car.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

16#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Car J moves twice as fast as car K, and car J has half tlpuj3 -at+7c6wdbjm z ,:oqw6 he mass of car K. The kineti :,m+l3zojjw ac 7tbqp -6wu6dc energy of car J, compared to car K is

A. the same.

B. 2 to 1.

C. 4 to 1.

D. 1 to 2.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

17#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object hits a wall and bounces back with halfevl, ;2e7rf (gfpjp 5s of its original speed. What is the ratio of g pev25 (fepjrfls,7;the final kinetic energy to the initial kinetic energy?

A. \frac{1}{2} \;

B. 1/4

C. 2

D. 4

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

18#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A brick is moving at a speed of 3 m/s 6os+w+pnuy3 kgsvjt0lu 0u n q0p,*8sand a pebble is moving at a speed of 5 m/s. If both objects have the same kinetic energy, what is the on 06j,g3 p*swu+p8n+ u k0utq ly0vssratio of the brick's mass to the rock's mass?

A. 25 to 9

B. 5 to 3

C. 12.5 to 4.5

D. 3 to 5

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

19#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 4.0-kg mass is moving with speed 2.0 ur9 v1pvgk1.f m/s. A 1.0-kg mass is moving with speed 4.0 m/s. Both objects encounter the same constant braking force, and are brought to rest. Which object travels the greater distance before stopping?.vrv1fkp 9u 1g

A. the 4.0-kg mass

B. the 1.0-kg mass

C. Both travel the same distance.

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

20#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

You slam on the brakes of your car in a panic, and skid a certain dista;a1xhe xfmk ub/ 3/nz5.9xge pnce on a straight, lev fb 3au.me1g hk9e5x//x np;xzel road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?

A. It would have skidded 4 times farther.

B. It would have skidded twice as far.

C. It would have skidded 1.4 times farther.

D. It is impossible to tell from the information given.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

21#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A planet of constant mass orbits the Sun in an elliptical orbit. Neglecting rxx) j*ufgu+ 6o m8ai-any friction effe*ig)xrx -m uj+fa86ou cts, what happens to the planet's kinetic energy?

A. It remains constant.

B. It increases continually.

C. It decreases continually.

D. It increases when the planet approaches the Sun, and decreases when it moves farther away.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

22#

问答题 ( 1.0 分) 切至整卷模式搜藏此题

State the work-energuf fxaxp9:qg6. )f- ca:e.ciwy principle.

该题自我估分: (必填) (满分:1.0分)

绑定到本题的附件链接:
绑定到本题的上传图片: (问答题类型题目图片/附件必须插入上方文本框，否则会被移除题目绑定)

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

23#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity mgy is

A. the kinetic energy of the object.

B. the gravitational potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

24#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity $\frac{1}{2} \; kx^2$ is

A. the kinetic energy of the object.

B. the elastic potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

25#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Is it possible for a system to have negative potential env7* v*;f* poft yw+duwf*ca)rergy?

A. Yes, as long as the total energy is positive.

B. Yes, since the choice of the zero of potential energy is arbitrary.

C. No, because the kinetic energy of a system must equal its potential energy.

D. No, because this would have no physical meaning.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

26#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object is released from rest*pt 2ycy q tl0(r5ikiip)/)s m a height h above the ground. A second object with four times the mass of the first if released from the same height. The potential energy of the second object compared t0ilt(k5q p ) t/*yry)mip2 csio the first is

A. one-fourth as much.

B. one-half as much.

C. twice as much.

D. four times as much.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

27#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 0.200-kg mass attached to the end of a sprinw4*la p.k/b hfg causes it to stretch 5.0 cm. If another 0.200-kg mass is added to the spk a4w*/f. bplhring, the potential energy of the spring will be

A. the same.

B. twice as much.

C. 3 times as much.

D. 4 times as much.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

28#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The total mechanical5zi kxn i*qu+f2h ag(7 energy of a system

A. is equally divided between kinetic energy and potential energy.

B. is either all kinetic energy or all potential energy, at any one instant.

C. can never be negative.

D. is constant, only if conservative forces act.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

29#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An acorn falls from a tree. Come+ua+4zck 4ay pare its kinetic energy K, to its potential energ a4eyzuk+a+4c y U.

A. K increases and U decreases.

B. K decreases and U decreases.

C. K increases and U increases.

D. K decreases and U increases.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

30#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Describe the energy of a car driving up a -*5wthv 7o/ng(fo: rk/vt ds uoz(d5b hill.

A. entirely kinetic

B. entirely potential

C. both kinetic and potential

D. gravitational

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

31#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A lightweight object and a very he0jw g)/p9 l4fkyrl; hbavy object are sliding with equal speeds along a ll9kw4 )ylg0h b fprj;/evel frictionless surface. They both slide up the same frictionless hill. Which rises to a greater height?

A. The heavy object, because it has greater kinetic energy.

B. The lightweight object, because it weighs less.

C. They both slide to the same height.

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

32#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Consider two masses w;sonk .ac6s c-ww b9ov/02 ql$m_{1}$ and $m_{2}$ at the top of two frictionless inclined planes. Both masses start from rest at the same height. However, the plane on which $m_{1}$ sits is at an angle of $30^{\circ}$ with the horizontal, while the plane on which $m_{2}$ sits is at $60^{\circ}$. If the masses are released, which is going faster at the bottom of its plane?

A. $m_{1}$

B. $m_{2}$

C. They both are going the same speed.

D. cannot be determined without knowing the masses

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

33#

问答题 ( 1.0 分) 切至整卷模式搜藏此题

State the principle of conservation of mechanical energy e3d5dos ms4a :for conservative forces.s3de:5 asm4d o

该题自我估分: (必填) (满分:1.0分)

绑定到本题的附件链接:
绑定到本题的上传图片: (问答题类型题目图片/附件必须插入上方文本框，否则会被移除题目绑定)

参考答案:

进入本题讨论区，参与讨论

标记此题

34#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A ball falls from th3j)vhvzpyry*r .8(gwl bb2sfihe(8 0e top of a building, through the air (air friction is present), to the ground below. How does the kib v(yhypwl 0jrs8z (8) .3r2ihf e*vgbnetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?

A. K is equal to U.

B. K is greater than U.

C. K is less than U.

D. It is impossible to tell.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

35#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A ball drops some distance and gains 30 J of kinetic eydujr2jm11e5m, n pv6 nergy. Do not ignore air resistance. How much gravitationmj1muj2n16dr5 e ,v ypal potential energy did the ball lose?

A. more than 30 J

B. exactly 30 J

C. less than 30 J

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

36#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A ball drops some distance and loses 30 J of gravitational potential en +p -igm9hlix.ergy. Do not ignore air resistance. How much kinetic energy did the lgi . +phmxi9-ball gain?

A. more than 30 J

B. exactly 30 J

C. less than 30 J

D. cannot be determined from the information given

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

37#

问答题 ( 1.0 分) 切至整卷模式搜藏此题

State the law of conservation ofe0v pumr8nz ux6.p( d* energy.

该题自我估分: (必填) (满分:1.0分)

绑定到本题的附件链接:
绑定到本题的上传图片: (问答题类型题目图片/附件必须插入上方文本框，否则会被移除题目绑定)

参考答案:

进入本题讨论区，参与讨论

标记此题

38#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The quantity Fd/t isbi9i0 7a0 rbid0f7ioy

A. the kinetic energy of the object.

B. the potential energy of the object.

C. the work done on the object by the force.

D. the power supplied to the object by the force.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

39#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

What is the correct unit of powty az- 3qum(i) ;bbyu(r v5(wker expressed in SI units?

A. $kg m/s^2$

B. $kg m^{2}/s^2$

C. $kg m^{2}/s^3$

D. $kg^2 m/s^2$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

40#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Of the following, which is not a (o ma( au;ojbf7i+/bsunit of power?

A. watt/second

B. newton-meter/second

C. joule/second

D. watt

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

41#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Compared to yesterday, you did 3 times the workap+lkda7a( (-i/ oh e6 pud/mx in one-third the time. To do so, youd 6p p+xhdeumlaa(a o(-i k7//r power output must have been

A. the same as yesterday's power output.

B. one-third of yesterday's power output.

C. 3 times yesterday's power output.

D. 9 times yesterday's power output.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

42#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

To accelerate your car at a constant acceleration, the car'2o *i5vxe iol ,fwt9*ps engine must

A. maintain a constant power output.

B. develop ever-decreasing power.

C. develop ever-increasing power.

D. maintain a constant turning speed.

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

43#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object is lifted vertically 2.0 m amm w44-7 j oj9(d,itixekuf.mnd held there. If the object weighs 90 N, how much work was done in lifting it?4k.iuwef tj(4,di 79xm mjm o-

A. $360 \; J$

B. $180 \; J$

C. $90 \; J$

D. $0 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

44#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

You lift a 10-N physics book up in the air a di.brr gra/6d+jh +fut .stance of 1.0 m, at a constant velocity of 0.50 m/urrjt..agf hr/ b6d++s. What is the work done by the weight of the book?

A. +10 J

B. -10 J

C. +5.0 J

D. -5.0 J

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

45#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 500-kg elevator is pulzrl+9q1th5jo q(l8 nuled upward with a constant force of 5500 N for a distance of 50.0 m. What is the work done by(+q1 zn8o ltjr qul59h the 5500 N force?

A. $2.75 \times 10^{5} \; J$

B. $-2.45 \times 10^{5} \; J$

C. $3.00 \times 10^{4} \; J$

D. $-5.20 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

46#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 500-kg elevator is pulled upward with a constant force of l6b8lyn9+ )o2sx vgev5500 N for a distance of 50.0 m. What is the work done by the weight of ebo9 vsx)62 nygv8ll+the elevator?

A. $2.75 \times 10^{5} \; J$

B. $-2.45 \times 10^{5} \; J$

C. $3.00 \times 10^{4} \; J$

D. $-5.20 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

47#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 500-kg elevator is pulled yx;yx)s 3rpy9,z1dxu u 9gvw1 upward with a constant force of 5500 N for a distance of 50.0 m. Wh ; y9vx r y9pdwzyx,suu13g1x)at is the net work done on the elevator?

A. $2.75 \times 10^{5} \; J$

B. $-2.45 \times 10^{5} \; J$

C. $3.00 \times 10^{4} \; J$

D. $-5.20 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

48#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 30-N box is pulledprv++m;ep jhou.cad - kwn/+sv3kk ;5 6.0 m up along a $37^{\circ}$ inclined plane. What is the work done by the weight (gravitational force) of the box?

A. $-11 \; J$

B. $-1.1 \times 10^{2} \; J$

C. $-1.4 \times 10^{2} \; J$

D. $-1.8 \times 10^{2} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

49#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 4.00-kg box of fruit slide25) mc3q,dz zsoj;omq s 8.0 m down a ramp, inclined at $30^{\circ}$ from the horizontal. If the box slides at a constant velocity of 5.00 m/s, what is the work done by the weight of the box?

A. $157 \; J$

B. $-157 \; J + 78.4 \; J$

C. $78.4 \; J$

D. $-78.4 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

50#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Matthew pulls his littdk xz;:rujyj z u6iv t0(l9(7fle sister Sarah in a sled on an icy surface (assume no friction), with a force of 60.0iyrx;utlv96uzkf 7 d(j z:0j( N at an angle of $37^{\circ}$ upward from the horizontal. If he pulls her a distance of 12.0 m, what is the work done by Matthew?

A. $185 \; J$

B. $433 \; J$

C. $575 \; J$

D. $720 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

51#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an object in the direction of the force. The graphvpah yx2;cmj0 ws)(s+ in Fig. 6-1 shows the force versus the object's position. Find the work done when the obh as+mpx y 0;)cjv2ws(ject moves from 0 to 2.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

52#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an objec6n3wkjs 0,u c+ev bq0uwjtm3*t in the direction of the force. The graph in Fig. 6-1 shows the force versus the object's pce*0bmquv +6sj3 , kt0 ww3jnuosition. Find the work done when the object moves from 2.0 to 4.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

53#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an object in the direction of the force.d21cac/ lzcc 3 The graph in Fig. 6-1 shows the force versus the obclc3c12ca /zd ject's position. Find the work done when the object moves from 4.0 to 6.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

54#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force moves an object in the direction of the force. The graph aqy 2+v )nfe/pq,t+fg in Fig. 6-1 shows the force versus the object's position. Find the wo,g pqn)qvff/ +etay2+ rk done when the object moves from 0 to 6.0 m.

本题所包含的其它图片:

A. $20 \; J$

B. $40 \; J$

C. $60 \; J$

D. $80 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

55#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A horizontal force of 200 Nlqg+:h 7aq0ho kk:ii:h t a6,o is applied to move a 55-kg cart (initially at rest) across a 10 m level surface. What is the final kinetic eht:o agk,ih l0aoq7:+: hq6 iknergy of the cart?

A. $1.0 \times 10^{3} \; J$

B. $2.0 \times 10^{3} \; J$

C. $2.7 \times 10^{3} \; J$

D. $4.0 \times 10^{3} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

56#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A horizontal force of 200 N is applied to move a 55w jx4y b-mcc gph1a2 69q-sj*t-kg cart (initially at rest) across a 10 m level surface. What is the24-9abp *tjs1qm h - xjcw6ycg final speed of the cart?

A. 73 m/s

B. 36 m/s

C. 8.5 m/s

D. 6.0 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

57#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 10-kg mass is movih (- 5 4hczuqof9kfy,png with a speed of 5.0 m/s. How much work is required to stop the mas9ph(u4zfh kfo 5,-c yqs?

A. $50 \; J$

B. $75 \; J$

C. $100 \; J$

D. $125 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

58#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

If it takes 50 m to stop a car initially moving gj;i5sy4pp8v).l6 jvk zlsk 6 at 25 m/s, what distance is required to stop a ca.8ykv)66gplp 4 ;ijkls 5jvszr moving at 50 m/s under the same condition?

A. $50 \; m$

B. $100 \; m$

C. $200 \; m$

D. $400 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

59#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A spring-driven dart gun propels a 10-g da66ktyma v t+* qq5r+kl7k rks)rt. It is cocked by exerting a force of 20 N over a distancrk6asqmk)7*tl5ktryk+ v6 + qe of 5.0 cm. With what speed will the dart leave the gun, assuming the spring has negligible mass?

A. 10 m/s

B. 14 m/s

C. 17 m/s

D. 20 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

60#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 100-N force has a horizontal component of 80 N and a 3nx2fd) ;sf1 2 vvg;sbsk* pv ga(mm1yvertical component of 60 N. The force is applied to a box which rests on a level frictionless 1fgmbk gy);v vmvn3s21pf2;xsa (ds*floor. The cart starts from rest, and moves 2.0 m horizontally along the floor. What is the cart's final kinetic energy?

A. $200 \; J$

B. $160 \; J$

C. $120 \; J$

D. zero

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

61#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An arrow of mass 20 g is /z*w +5pgutiqshot horizontally into a bale of hay, striking the hay with a velocity of 60 m/s. It penetrates a depth of 20 cm before stopping. tz5g iq*p/ w+uWhat is the average stopping force acting on the arrow?

A. $45 \; N$

B. $90 \; N$

C. $180 \; N$

D. $360 \; N$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

62#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 15.0-kg object is moved from a height of 7.00 m above a floor;l2xsy vs+dinpo/.ye 79 4 z0z6bcxhc to a height of 13.0 /9sl ccz n4;0ox7x+ dip.h2s6yvzy b em above the floor. What is the change in gravitational potential energy?

A. zero

B. 1030 J

C. 1176 J

D. 1910 J

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

63#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 400-N box is pushed up an inclined plane. The plane ish)n9)pobbn ceoh +8nl /6;cqigg,n2l 4.0 m long and rises 2.0 m. If the plane is frictiob cn/ i nn)h+gqleg98)c h26plnbo;,onless, how much work was done by the push?

A. $1600 \; J$

B. $800 \; J$

C. $400 \; J$

D. $100 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

64#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 10-kg mass, hung onto a spring, causes the spring to stretch 2.0 cm. What 2ibt,dvle a6gh fa0ho19t3;u is the spring con,e9th;gua aoh6 f20i31 tv bdlstant?

A. $4.9 \times 10^{3} \; N/m$

B. $5.0 \times 10^{3} \; N/m$

C. 20 N/m

D. 2.0 N/m

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

65#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A spring is characterized by a spring constant of 60 N/m. Htl,yn:e.u p.bwl,cz 8ow much potential energy does it storeu.y,t, . lnlbe pc8wz:, when stretched by 1.0 cm?

A. $3.0 \times 10^{-3} \; J$

B. $0.30 \; J$

C. $60 \; J$

D. $600 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

66#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

Calculate the work required to cot/ zasm0,+6w6* j ljgyvmob)fmpress an initially uncompressed spring with a spring constant of 25 N/m by 10 ct6mzom*6s0vgw,jya+ b)f /jl m.

A. $0.10 \; J$

B. $0.13 \; J$

C. $0.17 \; J$

D. $0.25 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

67#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

What work is required to stretch a::7yaqg.en cplx)g2n spring of spring constant 40 N/m from x = 0.20 m to 0.25 m? (Assume the unstretched position is at x = 0.: y qc)lp:.a7ne2 gxng)

A. $0.45 \; J$

B. $0.80 \; J$

C. $1.3 \; J$

D. $0.050 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

68#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A spring with a spring constant of 15 N/m is initially compressedsiv.sulhnrpe97. her;u61 3g by 3.0 cm. How much work is required to compress the spring an additionasrphin;vru l7. su3ehe .961gl 4.0 cm?

A. $0.0068 \; J$

B. $0.012 \; J$

C. $0.024 \; J$

D. $0.030 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

69#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 60-kg skier starts from rest from the top wo o:x dzz/ymofdr;7q,e9 1boj*4z2l of a 50-m high slope. What is the speed of the slier on reaching the bottom of the slelzzo2 1fo7zqd;/ywj o4:r9 ,o xbm*dope? (Neglect friction.)

A. 22 m/s

B. 31 m/s

C. 9.8 m/s

D. 41 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

70#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A skier, of mass 40 kg, pushes oucu2 evf9m22r i.7 ufsff the top of a hill with an initial speed of 4.0 m/s. Neglecting friction, how fast will she be moving after dropping 10 m v29mu.2r i2u7fe ucsf in elevation?

A. 7.3 m/s

B. 15 m/s

C. 49 m/s

D. 196 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

71#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An object slides down tq+b) bqk:qp+63 mdsga frictionless inclined plane. At the bottom, it has a speed of 9.80 m/s. What is the vertical hek+pbt: q)3d6+ qqgs mbight of the plane?

A. $19.6 \; m$

B. $9.80 \; m$

C. $4.90 \; m$

D. $2.45 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

72#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 1.0-kg ball falls tb.bhji;b(sjrz)sef/ar .9 6(5 l jixlo the floor. When it is 0.70 m above the floor, its potential energy exactly e a 5b)le;rss i6i/(.(xbb9jzlf jhrj.quals its kinetic energy. How fast is it moving?

A. 3.7 m/s

B. 6.9 m/s

C. 14 m/s

D. 45 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

73#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A toy rocket, weighing 10 N, blasts straight up from ground level wie b*6 mmyn0en le55cb/th a kinetic energy of 40 J. At the exact top of its trajectory, its total mechanicenycmm6 5be5 le*0 n/bal energy is 140 J. To what vertical height does it rise?

A. $1.0 \; m$

B. $10 \; m$

C. $14 \; m$

D. $24 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

74#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A projectile of mass m leaves the ground with a kbyylx 2:;ti9d wa yn pt k9)5ur*tq)7vinetic energy of 220 J. At the highest point in its trajectory, its kinetic energy is 120 J.y aq:tki*ur9tx tl bv) y7952)dw;ypn To what vertical height, relative to its launch point, did it rise?

A. $\frac{220}{mg} \; m$

B. $\frac{120}{mg} \; m$

C. $\frac{100}{mg} \; m$

D. Impossible to determine without knowing the angle of launch

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

75#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A roller coaster starts from rest at a point 45 tv.z/iki4kw5:+ 2 vamn v zv(jm above the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at thv45 2m jkv.w+/vn z z(itkvai:e top of the next slope, which is 30 m above the bottom of the dip?

本题所包含的其它图片:

A. 14 m/s

B. 17 m/s

C. 24 m/s

D. 30 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

76#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A roller coaster starts with a speed of 5.0 m/s at a point 45 m abovq3-c rm)t-j gee the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of thec)trm q 3-g-je roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?

本题所包含的其它图片:

A. 12 m/s

B. 14 m/s

C. 16 m/s

D. 18 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

77#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A roller coaster starts auwg k.5xxtve ;5t1 rei8s +c5,ydcqq1 t a point 30 m above the bottom of a dip with a speed of 25 m/s (See Fig.5. eteuv,tqryd1sg 1w5c5xk+c 8;qxi 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 45 m above the bottom of the dip?

本题所包含的其它图片:

A. 14 m/s

B. 16 m/s

C. 18 m/s

D. 20 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

78#

( 1.0 分) 切至整卷模式搜藏此题

What is the minimum speed of the ball at the bottom of its swingathxsr51eafd cv: mk):li+(*8p ; fll (point

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

79#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A:2.2 m/s

A. 3.1 m/s

B. 4.4 m/s

C. 4.9 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

80#

( 1.0 分) 切至整卷模式搜藏此题

难度:2

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

81#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A pendulum of length 50 cm is pulled 30 cm aytrbvq1p57/ i way from the vertical axis and released from rest. What will be its speed at the bottom of its / 1p5t qbyvri7swing?

A. 0.50 m/s

B. 0.79 m/s

C. 1.2 m/s

D. 1.4 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

82#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 1500-kg car moving at 25 m/ .xj4nc/sibbz: nh 50zs hits an initially uncompressed horizontal spring with sp si5. nz4ch0/bznjxb:ring constant of $2.0 \times 10^6 \; N/m$. What is the maximum compression of the spring? (Neglect the mass of the spring.)

A. $0.17 \; m$

B. $0.34 \; m$

C. $0.51 \; m$

D. $0.68 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

83#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A driver, traveling at 22 m/s:u 7enmjre)y1, slows down her 2000 kg car to stop for a red light. What work is done by the friction:eune)yr7 1 mj force against the wheels?

A. $-2.2 \times 10^{4} \; J$

B. $-4.4 \times 10^{4} \; J$

C. $-4.84 \times 10^{5} \; J$

D. $-9.68 \times 10^{5} \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

84#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

The kinetic friction force between a 60.0-kg object and a horizontal surfa 4 b8 za.;zvig6gsdopaj2-6k vce is 50.0 N. If the initial speed of z8 -sb;2.pzg6kov aj6 d4vagithe object is 25.0 m/s, what distance will it slide before coming to a stop?

A. $15.0 \; m$

B. $30.0 \; m$

C. $375 \; m$

D. $750 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

85#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 12-kg object is moving on a rough, level suvr zr)8qxn2e1c18 q zirface. It has 24 J of kinetic energy. The friction force on it is a constant 0rz81ri 8ex nzq2qc)v1.50 N. How far will it slide?

A. $2.0 \; m$

B. $12 \; m$

C. $24 \; m$

D. $48 \; m$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

86#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A force of 10 N is applied horizontally to a 2.0-kg mass on a level surfagsnv,*dv t-* ace. The coefficient of kinetic friction between the mass and the surface is 0.20. If the mass is moved a distance of 10 m, what is the change in av*,dng v t*-sits kinetic energy?

A. $20 \; J$

B. $39 \; J$

C. $46 \; J$

D. $61 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

本习题练习全部题目来源于题库网 (https://tiku.one)，学生可自助刷题练习，扫右侧二维码加微信，获取学习资料，答疑辅导
教师可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力

标记此题

87#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 60-kg skier starts from rest from the top of a 50-m high slope. z6pw .l9qppp 5 If the work don5 l6.ppz9qpw pe by friction is $-6.0 \times 10^{3} \; J$, what is the speed of the skier on reaching the bottom of the slope?

A. 17 m/s

B. 24 m/s

C. 34 m/s

D. 31 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

88#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

An 800-N box is pushed up an inclined plane. The plan + t ,encxjxs-r202ypoe is 4.0 m long and rises 2.0 m. It requires 3200 J of work to get the box to the top of the plane. What wase- ,x2+y cjxrtno0s 2p the magnitude of the average friction force on the box?

A. $0 \; N$

B. non-zero, but less than 400 N

C. $400 \; N$

D. greater than 400 N

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

89#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 2.0-kg mass is released from resg5 +cu l12v3:(yzumfq 7ppdv4olhj(3hzc3pbt at the top of a plane inclined at 20e above horizontal. The coefficient of kinetic friction between the mass z +14 5(: jzqpougm23 3fd ycu7hplhlvbp3vc( and the plane is 0.20. What will be the speed of the mass after sliding 4.0 m along the plane?

A. 2.2 m/s

B. 3.0 m/s

C. 3.5 m/s

D. 5.2 m/s

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

90#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 30.0-N stone is dropped f *sqxd jg4n*1o5/cyoarom a height of 10.0 m, and strikes the ground with a velocity ofo qag s1c/*4ndxj yo*5 7.00 m/s. What average force of air friction acts on it as it falls?

A. $22.5 \; N$

B. $75.0 \; N$

C. $225 \; N$

D. $293 \; N$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

91#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

At what rate is a 60.0-kg boy using energy when he runs up asbmmsm 6 e2 sd60bo2ff9scf:4 flight of stairs 10.0-m highs: bd fmfc bm46ef s202o9s6sm, in
8.00 s?

A. $75.0 \; W$

B. $735 \; W$

C. $4.80 \; kW$

D. $48 \; W$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

92#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 10-N force is needed to move an object with a constyz,(g qow*z7b s ln+ e6htqjm+wllv j .4(+5mdant velocity of 5.0 m/s. What power must be delivered to the object by the forc *54slqo mz7jqb+jhe wt.6n +zdll(wv +(,mgy e?

A. $0.50 \; W$

B. $1.0 \; W$

C. $50 \; W$

D. $100 \; W$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

93#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

How many joules of energ/5aayx93ub mv8j+w - paeq1 aly are used by a 1.0 hp motor that runs for 1.0 hr? (1 hp yla-jbvx8ma1 +a3 pq/ew9 au5= 746 W)

A. $3.6 \times 10^{3} \; J$

B. $2.7 \times 10^{6} \; J$

C. $4.5 \times 10^{4} \; J$

D. $4.8 \; J$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

94#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A cyclist does work at the rate of 500 W while riding. How much foraflr6p k ;juvgb - 5e-,5fos-wce does her foot push with when she is traverk,oj- ;f5lf-a uwpe-5sb6gv ling at 8.0 m/s?

A. $31 \; N$

B. $63 \; N$

C. $80 \; N$

D. $4000 \; N$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

标记此题

95#

单选题 ( 1.0 分) 切至整卷模式搜藏此题

A 1500-kg car accelerates from 0 to 25 m/s in 7.0 s. What is the wxv*4 4j*wge8fnbj6daverage power delivered by the engine? 4bj4d*6xgwj nwf v*e8(1 hp = 746 W)

A. $60 \; hp$

B. $70 \; hp$

C. $80 \; hp$

D. $90 \; hp$

绑定到本题的附件链接:
绑定到本题的上传图片:

参考答案:

进入本题讨论区，参与讨论

账号		自动登录	找回密码
密码			立即注册

未使用图片

本次作答已使用

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50
51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70
71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90
91	92	93	94	95

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50
51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70
71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90
91	92	93	94	95

1	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30
31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50
51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70
71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90
91	92	93	94	95