97.01: A force F directed at an angle of θ above the horizontal bmvq2 wff9f0yuzmabbt b a.b2.,pq6:);h gz9is used to pull a crate a distance Da9.fbb9aypf0 g 2zmb t6bq); ,:qm.f hwbuvz2 across a level floor. The work done by the force F is

  97.33: A softball player catches a ball of mass m, which is movinc, yab w -*2z/hl/ zbjuu5kw:2no3xqrg toward her with horizontal speed v. Wanj3yuoh*/5-bxc / z:zl,kq 2r2uwbw hile bringing the ball to rest, her hand moves back a distanced. Assuming constant deceleration, the horizontal force exerted on the ball by her hand is

  99.14: A construction laborer holds a 20 kilogram sheet of wallboa ac. x9x5k pt,ko0hrh4rd 3 meter above the floor for 4 seconds. During these 4 seconds xrakxh,h4t k5.po c90how much power was expended on the wallboard?

  17.11: A 5.00 kg block slides with uniform acce,f4 ( xgfrle19n4fbz lleration on a horizontal surface for 5.00 s. The block’s kinl4 ffxnb (1l9fe4,rzgetic energy strictly decreases from 50.0 J to 20.0 J in this time.
What is the average speed of the block during the motion described?

  17.12: A 5.00 kg block slides with hm,+ 6b,eafu.pgw1c g 9y s6y+f7ofng uniform acceleration on a horizontal surfacy+goy gp+7.m n, 6s h6 f1f,fuawbe9cge for 5.00 s. The block’s kinetic energy strictly decreases from 50.0 J to 20.0 J in this time.
Which one of the following choices best represents the magnitude of the block’s acceleration during the motion described?

  16.11: A 12.0 N net force directed to the right is exerted on3un j0 x 3n:2aeuusprqgya0 /,iiy4a3 a 3.0 kg block for 5.0 s. The block was initially at rest and slides on a horin2y 0a33yi/ge04au uau qpnrx,ij :3szontal surface.
What is the speed of the block at the end of the 5.0 interval?

  16.12: A 12.0 N net force directed to the right is e;jyrokw na113xzs0 5jxerted on a 3.0 kg block for 5.0 s. The ba 5nr;s10jjow13kzxy lock was initially at rest and slides on a horizontal surface.
What is the kinetic energy associated with the block after the 5.0 interval?

  00.15: A student initially at reston a frictionless frozen pond thro/;kutrgxqh5 8j5p :+l m .uee3tn0binws a 1 kg hammer in one direction. After the throw, the hammer moves off in one direction while the student moves off in th:qg 0u5 8 i+;njtk nmbr.ehu/ex5lt3 pe other direction. Which of the following correctly describes the above situation?

  03.14: A fan blows the air and gives it kinetic energy. An hour after z7 sb-f 2l2uxmek*rq334u rnjthe fan has been-nqu34 2fz7l2r3sr*je mkx bu turned off,
what has happened to the kinetic energy of the air?

  09.05: At an instant, a block of mass 0.50 kg has a position ,hrir)ih u.ho- 2ej-d of 3.0 m, a speed of 4.0 m/s, and aniro,hhjr d)u-i 2he.- acceleration of $1.0\; m/s^{2}$ . What is the kinetic energy (in Joules) at this instant?

  05.05: A box of old textbooks is on the middle shelf in the bo 3yrq bqt u;7c,.b6 9v;u3gl5bp)yrwqzbrv:r okroom 1.3 m from the floor. If the janitor relocates the box to the shelf that is 2.6 m from the floor, how much work doesbb3cyryr)luq t b3;ruw6v gv:,;9z bqqr.57p he do on the box. The box has a mass of 10.0 kg.

  02.32: An automobile engine delivers 24,000 watts (about 3w;ha0-xw og9 j2 horsepower) of power to a car's driving xh o;9j0awwg-wheels. If the car maintains a constant speed of 30 m/s (about 65 mph), what is the magnitude of the retarding force acting on the car?

  09.13: In the figure to the right, a box moves with sqkz*cd p( +3tece j+ .x; 35nnapouh8npeed 5.00 m/s at the bottom of a rough, fixed inclined plane. The box slides with constant acceleration to the top o.pj8 ed;on 5 q e(x3+ccpzt+hnkuan*3f the incline as it is being pushed directly to the left with a constant force ofF = 240N. The box, of mass m= 20.0 kg, has a speed of 2.50 m/swhen it reaches the top of the incline.
What is the magnitude of the acceleration of the box as it slides up the incline?

  09.14: In the figure to the right, a box moves with s.ytnli;j zp* ske5rp7g .q(u4peed 5.00 m/s at the bottom of a rough, fixed inclined plane. The box slides with constant acceleration to the top of the incline as it is being pushed directly to the left with a constag ;rp4n.l.zspkeu5ti*jyq7( nt force of F = 240N. The box, of mass m= 20.0 kg, has a speed of 2.50 m/swhen it reaches the top of the incline.
How much work is done by the applied force F to the box?

  11.30: Two cars travel to the right, each starting from rest, alo9 u*caz0 org/w k69,eoa5w bsfng a straight road. CarA has twice the acceleration of Car B. After traveling a distancubcg 5rf /z* ae0skw,o9a w6o9e F, Car A has speed B. When Car B has traveled the same distance F, what is its speed in terms of B?

  12.07: What is the net force acting on the object during the time i5myq8anxu9n s/; 3uoxnterval of the acceleru u;smx5 nxn 8/ya3q9oation?

  12.08: Through what distance does the object move during the k1.h6j up7u tetime interval of the accelera 76hujpkute1 .tion

  12.19: The magnitude of the linear mo),z 9gv ynntj:kmp c3 1gi2s4vmentum of a 4.00 kg point mass is changed from 6.00kg.m/s to 14.0kg.m/s in a time interval of 6.00 s. What is the change in the kis ck pvynj4:g v2t3 ,)9z1mginnetic energy of the mass during this time interval?

  14.11: A crate gains 36.0 J of kinetic energy while its sp-x/gmv/om :f keed is increased from 2.00m/s to 4.00m/s. Which one of the following choices best represents the mass /f -mkv/:mg oxof the crate

  94.38: A force F at an angle θ abov yej6)oxdy.bjdl+ +cd 9saj 0inv/7e/e the horizontal is used to pull a heavy suitcase of weight mga distance d along a level floor at constant velocity. The coefficient of friction between the floor and the suitcase is μ. The work donecd+ s.n+/ /x) 60yielajjdv7j de9boy by the frictional force is:

  14.31: A toy crane exerts an upward forcez)s7ornn2),x:8p*bx9q9ng tftu; s0jycfb d and delivers a useful power output of 0.10 w to raise a block vertically at a constant speed. At what constant speed willxf 90p)snnubo r8j9d y,2q n fg7t;*z:s) btxc this crane raise a 0.20 kg block?

  12.18: A 1.00 kg object is released frmfau*v8(5)k r c.z yi. 7knily1v zi:nom rest near the surface of the Earth, the gravitational force acting on the 1.00 kg object by the Eartv v..a1lzkk uiin)r5(8z: cm* iyy7nfh does 10.0 J of work on the object as it falls 1.00 mto the ground, which one of the following choices best represents the amount of work done by the gravitational force acting on the Earth by the 1.00 kg object during the fall?

  96.18: A rubber ball is held motionles)f -r-oepyk.c1 s s-tvs a height ho above a hard floor and released. Assuming that the collision with the floor is elastic, which one of the following graphs best y-o sk)tpe-rc1s-vf. shows the relationship between the total energy E of the ball and its height h above the surface?

  07.06: A 500-kg car is mov v/bxjmmgsk4)1pml4 ,l d bp/0ing at 28 m/s. The driver sees a barrier ahead. If the car takes 95 meters to come to rest, what is the magnitude of the minimum average net force necessary bxb/gm04)mk p1,jldml v/sp4to stop?

  00.26: A 500-gram ball moving at 15 m/s slows down unifod ( 9f2a le*u.ftnuw.lrmly until it stops. If the ball traf. f (2a *utl.lwdn9uevels 15 meters, what was the average net force applied while it was coming to a stop?

  02.26: Consider two laboratory carts of different masses but lok q)w)84;oy9 aze aebbozcu y/4htc,:,nz)identical kinetic energies and the three following stat)hn)/w: ztbak,4 bou;e8oq cy9yazle4) cz, o ements. Which of the above statements would be correct?
I. The one with the greatest mass has the greatest momentum
II. The same impulse was required to accelerate each cart from rest III. Both can do the same amount of work as they come to a stop

  06.19: A 60.0-kgball of clay is tossed vertically in the air with an:efomd-5bmc* initial speed of 4.60 m/s. Ignoring air resistance, whacd b-m:oe* m5ft is the change in its potential energy when it reaches its highest point?

  06.20: A boy jumps from rest straight upward from a flat, stationary t69s c1iin(k2s f3rsxconcrete surface. The boy, of mass M, leaves the concrete surface with speed v and his center of mass rises a distance d to the highest pointi9 n s163s2rfsct(xki of the motion. How much physical work did the average normal force of contact (N) between the boy’ s feet and the concrete do on the boy?

  02.48: An object of mass M is dropc,()tfnoj/hq ped from aheightH above the ground. The object crashes into some soft earth and comes to rest by compressing the earth a distance of H/2. Assuming that air resistance is negligible, tn/(jh f q,)cowhat is the magnitude of the average constant force exerted by the ground on the object while coming to rest?

  12.48: An object of mass M is droppedp:g dl 4 7osvyaz, y1le6)b(gh from aheight H above the ground. The object bounce)zoa4lpy:y, dlh1 bg67 gsev(s off of a horizontal surface in a collision lasting time T. The object then rises upward to a maximum height H/2. What was the magnitude of the average net force acting on the mass during the collision with the surface?

  96.38: A pendulum bob mass mon a cord length L rwz3w)0yr25,r hsnd u 2yv :uo+szl5ris pulled sideways until the cord ma0yudr r uly,zs:5+nw 2 w s2rh)z5vro3kes an angle
θ with the vertical as shown in the figure to the right. The change in potential energy of the bob during the displacement is:

  03.49: A sled slides up a uniform incline of unknown angle. The sled, w ku2dyn z.;qb:ws 9b+bhich started at the bottom of the incline moving at 10.0 m/s, rises to a height of 3.30 m above its starting position and ydkwb b+ns;.qu b 2z9:momentarily comes to rest. The sled then slides back down the hill. What is the sled's speed when it returns to its original position at the bottom of the hill?

  06.09: A deliveryman moves 10 cartons from tl+mt1rst/ x2h he sidewalk, along a 10-meter ramp to a loadst2h+x/1 tm lring dock, which is 1.5 meters above the sidewalk. If each carton has a mass of 25 kg, what is the total work done by the deliveryman on the cartons to move them to the loading dock?

  12.16: A constant force F=50N 7dep/b2 ng v8k(as shown in the figure) is applied for the 6.0 meter motion of the box upward along the incline. The mass of the block is Md72b8vk /ngep=15 kg. Which one of the following choices best represents the work done by the force F onthe box for the motion?

  04.48: Two identical bowling balls A and B are ea uw,3cl4/fwbech dropped from rest from the top of a tall tower. Ball A isbf/ wu3c,ewl4 dropped one second before ball B. After ball B is dropped but before ball A strikes the ground, how are the mechanical energies of the two balls changing?

  11.28: A person throws an object of mass M strai8)sf;uyi2wod le/.l 0du5qno ght upward with an initial non-zero speed v. The object rises to a maximum height H above the launch point. The person now throws an object of mass 0.5M straight upward with initial speed 2v. In terms of H, to what maximum henud0dlois lfe/2 yo)w8 5;. uqight does the object of mass 0.5M rise above the launch point? Ignore air resistance.

  96.20: A force of 10 N stretches a 12i ymln(x :mj+xnt 70 h9sedvspring that has a spring constant of 20 N/m. The potential energy stored in the st2(nhdmvs 0l j+x x ie1n7ym:9pring is:

  97.10: A compressed spring has 16 J of potential energy. What is the5mi7 - rj e4)h0q8l3ve tlbctu maximum speed it can impart to a 2.0-k0j e ivrh48t53 -)bcumtql7leg object ?

  

  10.31: An object of mass M starts from ar n-nm9u64hlg;o07t1n1n ic / mxgwq rest at the bottom of a fixed incline of height H. A person decides to push the object up the incline in one of two ways with an applied force sc7l 4o qgam 0x1tg w16 hr-n9mnnn;iu/hown in the diagram. In each of the trials, the object reaches the top of the incline with speed V. How would the work done by the person on the block compare for the two trials? Assume the same constant non- zero coefficient of kinetic friction between the incline and the object for both trials.