Is it possible for an object moving with a constant speed to accelerate? Ex w nk;*r9pt+b3xpsdz5 plain.p5zk *9 dwnprt;bs+ x3

  Consider a particle movxnep -. c:.vfmtpm2a+ing with constant speed such that its acceleration of constant magnitude is always perpendicular to itsvn2m.x+cf.e:-ptam p velocity.

  An object moves in a circular path at a 4k2v; rzkt+q xconstant speed. Compare the direction of the object's velocity and acceleratiok+4k2; qzxvtr n vectors.

  When an object experiences -5atj ): qgwbap-n )tduniform circular motion, the direction of the acceleration is a)pd:tw)b gq- -5jant

  Consider a particle moving with constant speed such that i*h/**rfb 59po rb ed;t xofh-hts acceleration of constant magnitude is always perpendicular t fobh *p x9e*br-;t*/f5h hrdoo its velocity.

  What type of acceleration doe 2rdn (q- (f 5iml;o7az0pgspus an object moving with constant speed in a circular path exp(p2 f(ldp0r7nzm5-;s o qi ugaerience?

  What force is needed to make an object move in a c-fc/qsdm6m215p ,ffos0 br onircle?

  When an object experiences uniform circular kmlo dh5+.odr*c e n f/q5e9.zlrz4 j1motion, the direction of the net forceofjn4 /.5l mhzkrrdl+z*.qe9 c d51oe is

  A roller coaster car is on a track that forms a circular loop izedeb y7o(c ) sof04l,n the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its cens bo7d(z0)4e elf,c yotripetal acceleration at this point?

  A roller coaster car (x0 n:flowb(382 pm u/eymgg8imass = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact wimy (:i/8fxlgw3oengp8 0bu2m th the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive psz u+fefnq w/5b0*4 hthen follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him ifs ub */0hezqf5p4w n+s

  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 cu ,9m n+uk exrmr j2s331xedmy1rve of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius(fegic4 + 3czs r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the centrig s3ci+4 efz(cpetal 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 v. hior 5, tpx2m.t46wim Then it goes around a curve of radius 2r at speed im56wo,xmp4rth .2i t 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 rad (c wy;mjj,rp9ius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the roadp(;c yj 9,rwmj is equal in magnitude to

  Two horizontal curves on a bobsl kr k:u4+e/dujed run 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 radiusjk/u+4 :dk ure curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic k59sk y n.mm5hq:2ey mbobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "clim9qm yyms: 5mn25e. kkhb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path tov 7( it.08worw aisr2rrn9/xs have both centripetal and tangentio ai x8 rs w90nr7.trw/rs2i(val acceleration?

  The gravitational force between two objects is proportionalpthq 2 bm5x4*f to

  The gravitational force between two objects is invers;e5d uc8n9in nely proportional to

  Two objects attract each other gravitationally. If the distance beo iwq i+6ml-6si /u;nhtween their centers i+qn-i o is6;/u6 wlmhis cut in half, the gravitational force

  Two objects, with masse 5hcj4;hsu/k 6f t4)eqfdif1ns $m_{1}$ 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 masses2o7sbs z(f*;m llmp(d $m_{1}$ 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 universal gra/pdr) 7 bhf67zmv;vh mvitation.

  Compared to its mass on the Earth, the mass of an object r z,3odt5i o8 4 nlq(kz)snay9on the Moon is

  The acceleration of gravity on the Moon is z0jbzk )9)hwv-v( upb one-sixth what it is on Earth. An object of mauv)p-0z zbbj 9wh(kv)ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Eart*sv/t;e 1hxvu h's surface, the rocket's weight

  A spaceship is traveling to the Mo(bh; enh1w si yyb5nov /::zx +f89umion. At what point is it beyond the pull of Ea+ib ms5e9;hih: b 1z(n8fvxu yn:/y worth's gravity?

  Suppose a satellite were orbiting t8 g1 vgtkzz/2w r:hexxzd ;;+ehe Earth just above the surface. What is its cent/ etz2heg;dzvxxkw;8gz+1 :r ripetal acceleration?

  A hypothetical planet has a mass of ie;ful qcc :1 z*l1mivh14t a9c k(-yuhalf that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration 1hq9luifc(u1: ve *c1l c; iy4zkm -atdue to gravity at the Earth?

  The acceleration of grg ey/q.a5m. ld6u1kfcsu t.qp h7;d3ravity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's m 37uy. 1. d qe;d6.lkrhtpaqus 5cfm/gass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of -osl85oxg q:t:o9piv 1oe8 av1c k1dxplanet A. If planet A has mass m, what is the mass of plad xo8gt1o:1x9vq kvi:1 5cea-op 8 slonet B?

  Two planets have the same surface gravity, but planet/5oo4u +ps sjp B has twice the mass of planet A. I+spju5 4soop/f planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circ+kca b 1xtkc :d+t0bj 7xrq2:cular orbit (radius r) about a spherical planet (mass M). Whicjtk c2+ 7akrxxt+ c::1c0bbqdh expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the si 4ylm)i0(9k lh 4p ptn5efi3tame orbit. Compare the two satellite's 0)p35yipl tn4( 4ilf kit9 hemspeeds.

  A person is standing on a scale in an e;+jjo tzk-mh,0p* dg(jq. r gjlevator accelerating downward. Compare the reading on the scalem qjj.(zg*k+ odr-;j,0htg jp to the person's true weight.

  Who was the first pers(whtj8)c 5s2jatmzlk7jw5o 4 on to realize that the planets move in elliptical paths around thcwsht4t5(km78j) a jlz wo25j e Sun?

  The speed of Halley's Comet, while travelicxi d7qmd g;.x0 tv dt1n2g29lng in its elliptical orbit around the S7cimg0g2v29;l.dqndt 1x dxt un,

  Let the average orbital radius of a planet be R+:xk2 k5 lq bcverg(3j. Let the orbital period be T. What quantity is constant for all planets orbiting thebj ql:5v 2(e3ck+rkxg Sun?

  A planet is discovered to orbit around a star in thn shtdqn9ie *qb(- k6 h2yq::z7r;eo he galaxy Andromeda, with 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 new planet be eshbhqrtn qe;97o k(6iq-hyzdn*2: :, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defz5 jq :1reddm7ined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's averagm dqe 1z7jd5:re distance from the Sun?

State Kepler's laws.u-iyxe)5yz+snt h 1mg,uxh 4/

  List the four fundame9k -rb ygn42bxd)zic *ntal forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of eq4hhuw q o6h/h9k ,.wnno3e* radius 150 m. What is the accelerah4qh6o3 nwkwhno qe*uhe,.9/tion of the object?

  The maximum speed around a xaldwe ;f3f- 0v;f 3jylevel curve is 30.0 km/h. What is the maximum speed around a curve with twice the xy;-3f a;ejvf30dw fl radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on th(us:eyy(k6y ee perimeter of a bicycle wheel of:ee(yysyk (6u diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. 8cay0zrs3+6q ise7 no What is the centripetaleq i37a+ z6ss80 nyorc acceleration?

  How many revolutions per minuteugm wi3z9ykde* yzj- 2xd3+6 z must a circular, rotating space station of radius 1000 m rotate to produce xyzdz-9jyemk 3iz62 3gu*+ wdan artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m z/jf:k5h 6wsa6 kyx,eradius turn at 96.5 km/h. What is the centripetal force on the motorcyclaz f56: , ekshwkyjx/6e?

  A 0.50-kg mass is attached to the end of a mw q6lpx/9. 5iygz4 emcr n:a+1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed ofynxim/z5c :lrp. e 6w4gma9+q the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and wh mhe3+ydss)xmtd*:rx v 2)9joirled in a vertical circle of radius r. At the exact top of the pate d)x+3 svmm)yxor:t9 hd2 sj*h 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 string and whirlw;mzmze/) e .bed in a vertical circle /)zzmm eb .we;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 by

  A jet plane flying 600 m/s experiences an6vjn h,g-gp/y acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the pg,nv h/jy6-gplane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop bhbpx/-;9esy au xjf-i 0 f/)(b* qqznis beneath him(eqyn9p0 ;qxu/-b)a hi-b/z*sfx bj f) 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 sevenp7)v/ro ze vj.ivn.w. times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, .ow.)v7 vnievj.pr z/can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horsf s0vefkj*., a8gkd3 izontal curve with the tires on the verge of j.skf k3vg0,ed*a s8fslipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a speq/j- n u.lyaw.ed of 20 m/s. The centripetal force provided by frictiola nuq/-..yjw n is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a fl e1y,wvl .q:snat curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and thee1y wv,s nq:l. road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The7 o5 9;6ycu0nxwo mboy coefficient of friction between thenoc 9w0byomo6 7;5xyu 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 Olymp39itsxqgz *jkw :x2r5ic bobsled to negotiate a 100-m radius tx 9rjs2 gtz*w3qx:k5 iurn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at a 9+7/ak;k6xmjtgi jhc4zh 8r sg /2 hpe$45^{\circ}$ 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, bankedo,:bvgl/ h +agng+b dr+njen9*md.+z at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is kwj:0h.(scxl; 9av; xrgwhf. banked 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 , cwd77r lbz:6k jhgvyu6b,lp 16qw*w is revolving uniformly in a horizontal circle rcvwblpwb77wgd:ykhq*,,6 z l 6j1u6of radius 0.500
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 agqe t r5eup apyh951jc s/-i44rea, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a 4t 5 /9ipqes4 pg u-yea5ch1jrcircular 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 consists of a proton of mag :h.z/1xsq hoss $1.67 \times 10^{-27} \; kg$ 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 2;eefgbc;dr vvvt(49Earth, due to the Moon? The m(e;ft2 v b49ge;vdv rcass of 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 masses ars /0gu( x,y8lg r.xnfptl/mv*e movtv(ug8yfrm.0 nl/, lgs/p xx* ed to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distgsdc(- cz6 4jjance from the Earth will the gravitg j6jc(4d zcs-ational forces due to the Sun and 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 i052q)cal qfm n 0c u.ha4h;yy*f.gnpys $7.4 \times 10^{22} \; kg$ 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-walk" at a distance above the Earth eqfrjl qp;o q2r t:.z9-w/tj6vi ual to the radius of the Earth. What is h9 lv:w;fp/to q6 z.rtjrij -q2er acceleration due to gravity?

  The radius of the Earth is R. At what distance above theffv7tad88t4g Earth's surface will the accelerationff487t 8 dgvat of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above it z6qvi shuute;h.y ) -7)ez/yls surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface o)yz6-v.s7 u e/zlht)y h;iu eqf Mars, is

  At a distance of 14000 km from tga*da( /e41.kt kl vxsome planet's center, the acceleration of gravity is a*v.1( tdetkga4 l/xk$32 \; m/s^2$. 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 Earth. The Earth has radius slkpjb.*9wr11gy: r y)9m ezz r. If the object is raised to a heig9skzr) byg *r1p 9.mewz1lyj :ht of 3r above the Earth's surface, what is its weight?

  By how many newtons vd p*9(l jd8mwdoes the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth m jdd9v8wp(l* is $6.38 \times 10^{6} \; m$.)

  The Earth has radiuss y: y-ifqp 2f.5cbom +q3y0ze r. A satellite of mass 100 kg is at a point 3r above the Earth's surface-f0mizp2 os eqf yq.5+y3c:by. What is the satellite's weight?

  A spherically symmetric planet has f5 9(glqrwti8g.d+t meour times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of t+g8qte tl .d(gm5w9 irhe Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the sameq +qbgtg.b9*a line, with q*. +gtaqbbg 9the Earth between the Moon and the Sun. The Moon has 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 the3x9bd rgtk g7( 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 aboutdjt;b6 rl9 q 16. gik0vdfyej7 the Earth (i.e., it just skims the surface of the Earth). Whkr.qv ij;7d6tgd1 eyf 06b9ljat is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit an;nx qx)scd30j:xpl5 bout the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The xlsjc; 0dqxn3:x ) pn5mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the fgq0y 2faax e9u9nm0(Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The ae(nfgx09f ymu90 2aqmean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, h5 ;xnf ijx;19nc6nakszb7t0 las an 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 orbiisq0 n58av3l uk0. d ty8o2wjits the planet with 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 ciri ;i3fz9zsc 9w 59;/pnyrhkrdcular orbits. Moon A has orbital radius r, r k9;pswiiy3;z/ 59rc zd9 nfhand moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ik8:olkfb0r f9(l 0wvx s $7.78 \times 10^{11} \; m$ 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 Jupiter 12 years to orbit the Sun once. What is the aylcrv4q3 eufz (+.p;r verage distance from Jupiter l;3prq e4+f .rv(yuzcto the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)