Is it possible for an object moving with a constant speed to accelerate? Exgc bev gp6i9uu8 jbi 2fc/-q40plai/j8viq fueb2gp 9-cbugi 46c0n.

  Consider a particle moving wi1qih.89hs yec th constant speed such that its acceleration of constant magnitude is always perpendicu.c s1q9hh iy8elar to its velocity.

  An object moves in a circular path at k.5dw8 oesdob;sq /d7 a constant speed. Compare the direction of the object's velocity and acceleration vect/5d. qdob 7se;sw dok8ors.

  When an object experiehcf a6e9da;c5nces uniform circular motion, the direction of the accele9d e5ah f;6ccaration is

  Consider a particle moving with constant speed -lw (ild/p.geqlh ; d.such that its acceleration of constant magnitude is alwa/lged.id.w(hl q;l -p ys perpendicular to its velocity.

  What type of acceleration does /;e389er )a lheebooj an object moving with constant speed in a circular path experience? ;elbee /oeor8j 39h)a

  What force is needed to make an object move in a cir1pijira yo :::cle?

  When an object experiences uniform circular motion, the direction of the net form9q1xes pwc+c* uifd78yd +;g cm f9;cewdyg*+ 7qu+ 81pcdisxe is

  A roller coaster car is on a track that forms a circular loop in the1p v,yz/we9p6e .zmz d vertical plane. If t6dw.z 9pz yp,emvz1e /he car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a tracg.5 nd 8v.51bztnji lgk that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, what is the minimum g.lnjd8igz.bn5 t15 v value for its speed at that point?

  A pilot executes a vertical dive then follows a sel k;8eg2q, 3mqxcgy5 gmi-circular arc until it is going straigheg, 2xgm83k lgy5q; cqt up. Just as the plane is at its lowest point, the force on him is

  A coin of mass $m$ rests on a turntable a distance $r$ from the axis of rotation. The turntable rotates with a frequency of $f$. What is the minimum coefficient of static friction between the turntable and the coin if the coin is not to slip?

  A car goes around a curve of rt; ucno*p2;o+lsvb+ qadius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius r at a constant speed v. Then85vrkhi ze)2a it goes around the same curve at half of the original speed. What is the ceeh8 i2)za5 rkvntripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed ca/ 0yw4h8xp cv. Then it goes around a curve of radius c4/ 8hcxwp 0ay2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radiui(c0b eys53e ps r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal componeep0 isc ey5(3bnt of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled gigy ld+,e) s1run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve is v. What is the si1lg+ d)e,ys gafe speed on the larger radius curve?

  The banking angle in a t:1xfur00km( uh,sgy smvl. 6hurn on the Olympic bobsled track is not constant, but increfu yrhl s0 (hmm:0vx6 ku1g.s,ases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object movingq1j58 y+ywnbd around a circular path to have both centripetal and tang jbqnyd815+yw ential acceleration?

  The gravitational forceipp;w apqg ;gdnv s- ;6e), ibd;poc;8 between two objects is proportional to

  The gravitational forgis9 b:mnw2: lce between two objects is inversely proportional to

  Two objects attract each other gravitationally. If th6g,87m l rkpdqe distance between their centers is cutgq8 prkml6d7, in half, the gravitational force

  Two objects, with mass d(wxtmbv)i90qpj gq5/ 5m;z fes $m_{1}$ and $m_{2}$, are originally a distance r apart. The gravitational force between them has magnitude F. The second object has its mass changed to 2$m_{2}$, and the distance is changed to r/4. What is the magnitude of the new gravitational force?

  Two objects, with ma0hfa re*ed 65usses $m_{1}$ and $m_{2}$, are originally a distance r apart. The magnitude of the gravitational force between them is F. The masses are changed to 2$m_{1}$ and 2$m_{2}$, and the distance is changed to 4r. What is the magnitude of the new gravitational force?

State Newton's law of univt+ 2;6zpztz ycersal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moo7 yr+sxwv 7 jik8bkz90n is

  The acceleration of gravic.v4+tlmn-atwep 9 o+ ty on the Moon is one-sixth what it is on Earth. An object on+pcv at w om.9-l4e+tf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rn:l-; (djtmo x/) ymltocket's weight

  A spaceship is traveling to the Moon. ,blhq m9im :9l At what point is it beyond the pull of Earth's gravitmblhq9i 9l:, my?

  Suppose a satellite were orbitixd+x 7;l kznd /q znhoajv(w5 2qj*i2;ng the Earth just above the surface. What is its cix dl5jqz q7xdznk2;2 ; j+wao /vnh(*entripetal acceleration?

  A hypothetical planet has a mass of half th ) g0jcske*3hlat of the Earth and a radius of twice that of the Earth. What is the acceleratl)c3e hgkj*0sion due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on u.6cho ii kv at2pf*9e5krx,xu* o(q3Earth. The radius of the Moon is one-fourth that of the Earth. What is the M 56uuoi.vqck f*hxatk 9xr3*(p ,ie2o oon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius oow;m6ny asakr0rf3.ij1 c4l7f planet A. If3cafy; 1sn.4ijmrw7o l a kr06 planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity,5ethnj 13k 8 7rijmpk;p;i5pq31 yhgn but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of 5n;tmj e3g;3h r8qpp ip71jkhnk15yi planet B?

  Consider a small satellite moving in a circular orbit (radius r)j 6bmw6 b,jj0 fqa5i2n about a spherical planet (mass M). Which expression gives this satellite' aq5mjbfj6,nbj 0wi 26s orbital velocity?

  Satellite A has twice the mass of satellite B, and rotat(h t4z n8yu 9c2zjzt nctdw,89es in the same orbit. Compare the two satellz ncth9( w8z jzntdt 94uy82,cite's speeds.

  A person is standing on a scale in an elevator accelerating downward.26g.ezjlcclmr6jv0/j/ki(o lxpy)7 ,tca e 2 Compare the reading on the scale to tzjt .k,/26c y o m)iv( gcc7e2elxljj/pr06a lhe person's true weight.

  Who was the first person to realize that the planets move in elliptical patwi;qj g ,g lm4+a.qu)* jfl,wljql)6yhs around y+a)q6l4uj;. q*qgjj lll),,imwgf wthe Sun?

  The speed of Halley's Comeno,*-a axwl3ot, while traveling in its elliptical orbit around the Sun-oxaa ,lo3 n*w,

  Let the average orbital radius of a planet be R. Let the orbit+ r4)ta0c tp2fyno :wval period be T. What quantity is constant for all planets orbiting the r4)np vatc: 0 2f+woytSun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, wits5fssh. 05 nfbh the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the period of revolution of that new05fhssns bf .5 planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the8;0w3ccbofyv( ytp ,f Sun is defined as one "astronomical unit" (AU).3,cf ;(b0t8wfyo cvp y An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.;0+)dafji6 mm+ej n yh /ark(t

  List the four fundamental forces in natu2bsax.3 vimv)y(q/ fkre.

  An object moves with a constant speed of 30 m/s on a circular trac2 dvdf hj)w5hf(o/h9vk of radius 150 m. What is the acceleration of the objectd2)vof 59vj/dhhf (wh?

  The maximum speed around a level curve is 30.0 km/h. What is the mwqg jpl1)-dte y; f+)l f v69wuc:n.ftaximum speed aro fw1n:-we .dftjplq+ )cvf69)tguy; lund a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perp(-3 2 w:ary-gmb:ict pwtwp0o eb36kimeter of a bicycle wheel of diamete c3m yp3wt-w ogb0k-pa:ribt6(pe2: wr 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel ro:jpnt (7fw;zo 1z j1ontating at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal aptzow; jf jzo 1:1(7nncceleration?

  How many revolutions per minute must a circular, rotating spam ,6*hty-+fvhjjo 7 lsce station of radius 1000 mtohv6+ y*j l7hsmj,-f rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a ev51pd5zx05wk m+hs)iye qwq p *5,wu13.7 m radius turn at 96.5 1e*0i5udz5,xq5whve5w ksp p q+ m)ywkm/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attachedfd g5hlo((2r 0 3egqsp to the end of a 1.0-m string. The system is whirled (lqodsg0f 2reph3 5( gin a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and ww:q lrrt(g):tc0/ tev+ gp2zwhirled in a vertical circl t0 rtvclwgt(2rwz)peq+ / g::e of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong strin0xan7l8dju 3jt)on ir.fj.rf8c q4a 3g and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weight. The stone's speed at this point is given byrcflofjrj.qn 4.aa8 7n ui3 tj0)3 xd8

  A jet plane flying 600 m/s experienffj (sjl*0 :kkces an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which f:j0*fk(k j slthe plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop isb+ v6y/pvgmwqcf w zu8 s wj3:2lnp,)vgm+d14 beneath him)cv 6pwbuvfy q+ :wgsd zl3v) /4mw1m,+gpn82j of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven timesq15+ks k khft;(ca i8o his weight. What is the minimum radius of curvature that a jet plane's pka5;8 o fti1qksk (ch+ilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius h k )gq0.jdsa m+bnqt15orizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same cqkj+a ntg)5q 1s.0dbmoefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m-/tlo 0a ki.p pfk( 7ih2isa*m with a speed of 20 m/s. The centripetal force provided by fricl/0 mpo2.7htf *aaiipkk -(sition is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curvlxx4x0 11r tkfe of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction betweent l1fr1 xk0x4x the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a /;m8k:xwpkki58j ivvsv f0t 3 level curve. The coefficient of friction betvjki3 kxwi:8/ pm ;vfvs kt508ween the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate w ,(3d4j 26s m1cgdb* uz ufwmf8)afdg.flh 6va 100-m radius turn at 35 m/s without skidding? (Ignor6z * c13wg2 (8mjm gl)au6f .fuvd,sfb hfdw4de friction.)

  A horizontal curve on a bobsled 03xtnsemx1r 5ildc6 -, 1twsn run is banked at a $45^{\circ}$ angle. When a bobsled rounds this curve at the curve's safe speed (no friction needed to stay on the run), what is its centripetal acceleration?

  A frictionless curve of radius 100 m, km1z+jzcxgec:v 7g; 4 banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedzjxn fut64 ,y0u jw6)x at $45^{\circ}$. Suppose that an ice storm hits, and the curve is effectively frictionless. What is the safe speed with which to take the curve without either sliding up or down?

  A 175-kg ball on the end of a string is revolving uniformly bg*tu tn za. 1:wej)u-in a horizontal circle of radius 0.5-.z*u 1wg : jnaebtu)t00
m. The ball makes 2.00 revolutions in a second. (only fill in numerial value in the blanks)
(a) Determine the speed of the ball.    $m/s$
(b) Determine the ball's centripetal acceleration.    $m/s^2$
(c) Determine the force a person must exert on opposite end of the string.    $N$

  Starting from rest in the pit area, a rac(lxes ; u)n(p qt k1a1,jzi;jae car accelerates at a uniform rate to a speed )u,st((il zq jeaxakp; nj1;1of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value in the blanks)
(a) Calculate the tangential acceleration.    $m/s^2$
(b) Calculate the radial acceleration when the instantaneous speed is equal to 30 m/s.    $m/s^2$

  The hydrogen atom cons*1o ej dw29qv*q fzv;1lzs6 adists of a proton of mass $1.67 \times 10^{-27} \; kg$ and an orbiting electron of mass $9.11 \times 10^{-31} \; kg$. In one of its orbits, the electron is $5.3 \times 10^{-11} \; m$ from the proton. What is the mutual attractive force between the electron and proton?

  What is the gravitational force on a 70-kg person standing on the Earth, du( 7:yw; gx3bymlj;el he to the Moon? The mass ofyhl(7 m:ej g3x;b wl;y the Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. If the mny0)babji76 lasses are moved to) n70jyialb6b half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from t:y o ov7:a p/a;sk+kgphe Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun a o+:g:;ov/sk pypk7aand the Earth cancel?
Earth's mass: Me = $5.98 \times 10^{24} \; kg$ the Sun's mass: Ms = $1.99 \times 10^{30} \; kg$
Earth-Sun distance: r = $1.50 \times 10^{11} \; m$

  The mass of the Moon if* 2jr1fz tp*hs $7.4 \times 10^{22} \; kg$ and its mean radius is $1.75 \times 10^{3} \; km$. What is the acceleration due to gravity at the surface of the Moon?

  An astronaut goes out for a "space-walkgn7xh ha c2j05e6m4gs " at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gravit g2x 7ag4emc6jh5h0sn y?

  The radius of the Eart1fwv* n1iqn*mh is R. At what distance above the Earth's surface will the acceleration of gravity bfwnnvi1* 1m q*e $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its su cofhqg43* k+bbs+r44bneh(krface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared sg(b q4ob3r4*ckh n4+fk he+b to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the accelersa42zo7hdvhabgmh z 62wm 0 (2ation of gravity is hmabz26dzw2a2svho (7h 4mg 0$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface of the Eq/c 9jtzgmvm7r w p8si8 rz9/9arth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's sujc7sir r /vg 98mzz9/p8 tq9wmrface, what is its weight?

  By how many newtons dr,u45 xws ja1;z0f/n ab l ;t;jpfgvs,oes the weight of a 100-kg person change when he goes from sea1xl;aru5b; vj0wsz/s4j ,g t,pn;f af level to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of ymo.c w62 m7hb)ikb9u5zn:or mass 100 kg is at a point 3r above the Earth's surface. What is the satellitc :r ywuiz).5o6bhmmo92n7kbe's weight?

  A spherically symmetric planet has four times the Earth'rzbtvkp hj sf*3:3sho+88a 5bs mass and twice its radius. If a jar of peanut butter weighs 12 N on the zahv3p5s+:f3*r8h sbb j 8otksurface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Mo3+h kqb:f2xk y -s1bf3n8gqdc on, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon q+ g8fy3kqdf2bcs-n: b13kxhhas a mass of $7.36 \times 10^{22} \; kg$; the Earth has a mass of $5.98 \times 10^{24} \; kg$; and the Sun has a mass of $1.99 \times 10^{30} \; kg$. The separation between the Moon and the Earth is given by $3.84 \times 10^{8} \; m$; the separation between the Earth and the Sun is given by $1.496 \times 10^{11} \; m$.
(a) Calculate the force exerted on the Earth by the Moon, its magnitude is    $\times 10^{20} \; N$, its direction is  ----待选择----towardsaway from  the moon.
(b) Calculate the force exerted on the Earth by the Sun, its magnitude is    $\times 10^{22} \; N$, its direction is  ----待选择----towardsaway from  the Sun.
(c) Calculate the net force exerted on the Earth by the Moon and the Sun, its magnitude is    $\times 10^{22} \; N$, its direction is  ----待选择----towardsaway from  the Sun.

  A 2.10-kg brass ball is transported to theunc*q. ju:ru : 7oezkkkr1 6h2 Moon.
(a) Calculate the acceleration due to gravity on the Moon.    $m/s^2$ (The radius of the Moon is $1.74 \times 10^{6} \; m$ and the mass of the Moon is $7.35 \times 10^{22} \; kg$)
(b) Determine the mass of the brass ball on the Earth    $kg$ and on the Moon    $kg$
(c) Determine the weight of the brass ball on the Earth    $N$
(d) Determine the weight of the brass ball on the Moon    $N$

  A satellite is in a low circular orbit abfssfo31) (fm9fwm h +uout the Earth (i.e., it just skims the surface of the Earth). What is the speed of the s9+sf u3w hmo f(smf)1fatellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., ituupkldu. i7zd;1nj)jwd 5+6p/ ef)/ vyqwgf ) just skims the surface of thek6uep)d)w7d/zlyp5 1q;jff jg )n+ duwviu. / Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 2s.v;z6/ry- k1bmz ysu30 km above the surface of the Earth. It is observed to have a period of 89zm -sbu /1kzsvyr.y6 ; min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has aw j/ r5hfp0aw/;hb:eq n orbital diameter of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet withddu* 3k5c r9tj a radius of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly circulx/ jn5wj;yb 3 iyh4l1tar orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How l 541lw;h jjxby/y tin3ong does it take moon B to complete an orbit?

  The planet Jupiter is r:x3s1-w 9 ero/nsbrx$7.78 \times 10^{11} \; m$ from the Sun. How long does it take for Jupiter to orbit once about the Sun? (The distance from the Earth to the Sun is $1.50 \times 10^{11} \; m$.)

  It takes the planet Jupitpg1 a*)x hss;ler 12 years to orbit the Sun once. What is the average distance from Jsl)agsh* x;p1 upiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)