Is it possible for an object moving with a constant speed to accen.bv ;)cnc( izlerate? Explainn vi()n .z;ccb.

  Consider a particle moving with constant speed such that its acceleratioib : o+oagx83gn of constant magnitude is alwayso+bg io3a8g: x perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dyy-rtu**mgy 5 p3bv7a irection of the object's velocity ang7 uma -v p35tyyy*b*rd acceleration vectors.

  When an object experiences uniform circular motion, the direction of the anvu vu lfjl1;an0kw7- xi6u 90ccelerauvf;nl6uil0 0-w9 7 vx knju1ation is

  Consider a particle moving with constant speed such that its acceleration o b/.nkxb(xi l(f constant magnitude is always perpendicular to its velocity.(x/ .i(lx bbkn

  What type of accelerati m9c e f/0o)vpo8y8codon does an object moving with constant speed in a circular path y8vep c 90 o)ofcod/m8experience?

  What force is needed to make an object move in a circlezs.(q t dqf,.x?

  When an object experiences uniform cii o*x.t7 p(zjorcular motion, the direction of the net force z*op jt(i. x7ois

  A roller coaster car is on a track that forms a circular loop in the veu:m1h 8ovmuga14g2 pu,h q3s yrtical plane. If the car is to just maintain contact with track ah uqs2 ovg1 g 1:hpm3uu,m48ayt 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 track that forms a circular lz,l f wqco9a)ft788)vl ,fmcn oop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, what iscv78nltfo wz, lc9m, f)q8af ) the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-0r5gyte fuk 81 ssv0g83evqf0circular arc until it is going straight up. Just as the plane is at its lowest point, the forkf0 sqefrgetg08 vsy1u3580v ce 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 cur*kfm .aj;e9szk ,b 8wuve 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 r at a constant speed v. Then it goes arougsr+ mchml-lg 6fi8.f ;ya9g0nd the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first timly9m.-sfmg 0ig; la+6f8hcrg e?

  A car goes around a curm .poz +1ncif4ve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to thec onp+fm4zi1. first?

  A car of mass m goes ge0dq31x m6q d,wvl*faround a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate thd q0wxlvgdm6e ,*q 13fe curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are ban:q );s;vkj6yask jz9*1 zocw yked 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 9 zk*;ssjq)vw1 ; k:joyaczy 6the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled tr ynlqdbp067, dack is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then g6pl ,0ndqydb 7o lower coming out of the turn. Why do they do this?

  Is it possible for an objef- 0c gbs0 shta0hap+.cxf: 1lct moving around a circular path to have both centripetal and tangential a b0psa g.lhcf0 x-h:+1fs0ta ccceleration?

  The gravitational force between two objects is proportd6,zbr mmrxdjq434 krvtp:-* /gn9t g ional to

  The gravitational force between two objects is inveryw5jcw*,vty7*v. cr xsely proportional to

  Two objects attract each other gravitationally. If the dim f)lh3qqrkvwj yx)e3x 13)- jyi-q 1istance between their centers is cut in hmi ix)q-1q jx k3 yvj fw3)-yqr3el)1half, the gravitational force

  Two objects, with massey,),5sdnwdkqp t2; dms $m_{1}$ 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 mam v ,f9* qr,i;hvhrgla+a jp72sses $m_{1}$ 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 gravitation5,v()w ktu ftk.

  Compared to its mass on the Earth, the massbzuv 2 yk,()fm:ax7oh of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what i964b cnkbbza a*)v*x et is on Earth. An object6* 49vnb)*z a akxbecb of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from theg0 mtak id6 cusi*bv n.-,ok;8 Earth's surface, the rocket's weight

  A spaceship is travelingnm8:/f 4c 9pgekcd+ te to the Moon. At what point is it beyond the pull of Earth's grc ekp/9n 84d: ct+egfmavity?

  Suppose a satellite were orbiting the Earth just above the su uq3 .ke8fr dt8.t:qegrface. What is its centri:tf.qet8ge 8k 3q r.dupetal acceleration?

  A hypothetical planet has a mass of half that of the Eh :iw(r,o4go;ld-sr ugr/1 jkarth and a radius of twice that ofd; 1irol gwrhks:(4rgj-,/uo the Earth. What is the acceleration 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-six* 32paso)e 5-sxu pkurth what it is on Earth. The radius of the Moon p5r -x2spaos) k*3uueis one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius o. qnl:y;g sq5jf planet A. If planet A j .s5qyq:g;ln has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, butq.w 2h-x+ ptgyz,.jfz12 +awlpuioc 1 planet B has twice the mass of planet A. If planet A has radius r, what is the 1p,+ x +.p.l1 qychww uzjot -2az2gifradius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sphe rwhv91 jlwfr*1t fw3f/9ww-f yb5bk. rical planet (mass M). Which expression gives this satelli f wkfbhv/9yfb1.www 3fr5r* jl1wt9-te's orbital velocity?

  Satellite A has twice the mass of snw7 oubpd:.(tpy.b0a.px )f;sax 9te atellite B, and rotates in the same orbit. Compare the two satellit dbs ow9.xpbtt (70;u. p.e n:xy)fpaae's speeds.

  A person is standing on a scale in an elevator accelerating downward.h)-+ qis-gnlxpb 8v7e Compare the reading on the scale to the persoxv-l hg )nepb -qsi8+7n's true weight.

  Who was the first person to realize tha x brfuikt60d77lo7;m t the planets move in elliptical paths around the Suli7 x f6bktr0mo77u; dn?

  The speed of Halley's Comet, while traveling in its elliptical o )db3 geb d0.*rz:6eexp 9waumrbit around the Sun,weap3ge*db x:eb09r u6z) d. m

  Let the average orbital radius3tsi5 k caj-3c of a planet be R. Let the orbital period be T. i53t3k-a sccjWhat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, wit/zalv7i 7 7mith 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 zl imtav /77i7be, compared to the Earth's orbital period?

  The average distance fbea:5h2xdp8 r rom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in o:prebdh 825xane-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.w ;rie*m p83 u(e-v5hfq9ja xh

  List the four fundamental forces in nature.) 3cxxy7..(c; ykh sud /lqzpe

  An object moves with a constant speed of 30 m/s on a circular track n. is pptmoi9f7h.ul4*8ozh+of radius 150 m. What oiipsl f8m*+pzu 4.hot79.hnis the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum s .qotglord+yz (52*8z ukv:dmpeed around a curve withotz.82qo:+zm5ud rydkl ( v*g twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration off wz*qz4)va m*ft,+sv a point on the perimeter of a bicycle wheel of diameter wzf*aq )tmz f,sv+*4 v70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotatingwuf4un7(d7-:rq ik- u g z3ko e2 3fz*+zkfewj at 5.00 rev/s is located 0.200 m from the axis. What is k7k3nzu*k4jzfuufzwr o327i:f-dw-eg+qe ( the centripetal acceleration?

  How many revolutions per minute must a circulmn75b j-,sawdnb/- .l eckr3xar, rotating space station of radius 1000 m ro-j/kbd3a- lscrw, ebn5x .n7m tate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around asbdp) ubz.am6/ 6unq+ 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motdn bp.ub +6m/s 6quaz)orcycle?

  A 0.50-kg mass is attached to the end of a 1.0-ozx zx-o8co53 4b( j ks:k;bfem string. The system is whirled in a horizontal circular path. If the maximum tension th-5;bx3ckfz :8oe4bk( jxzs ooat 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 whirled in a t :i4udgiq 6y 6ae(w8ac :dn6evertical circle of u4egqe66a inw(a68:ddtciy : 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 topa8hp)i ano8e//*btcdq *b7x a strong string and whirled in a vertical circle of radius r. At the exact bottotnpx/ a*i h7bc )p*8b/a 8eqodm 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 60)qaj qfdp. 1o e5ki/j*0 m/s experiences an acceleration of 4g when pulling out of the dive. What is the r*qkje5ojp)ia.q d /1 fadius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which t)mi7qs2gk 9cq1 -armdeesd1ac (31zdhe center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-haq3ag1smcd-q1 c 7i mz2sa9dre1ek) d(lf of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What isa 1*-+5ktp r6 dqt*cg ykjaqp5 the minimum radius of curvature that a p-5t+ *6r j1dkc yqaqp*at5kgjet plane's pilot, 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 horibk-k95la7k;+ squya lio94i xzontal curve with the tires on the verge of slipping. H5k qa7+ 4-ulsklo9yiikx;ba9ow 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 speed of 20 m/s. fvy( 4pis/ln+6a7z9h mg i4cm(e/ e, np3cjkjThe centripetal force provided 37lje4/mp6(jk94i(myf ng ncv phaei/cz+, sby friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radiu c,/ mkx adb:j6ae0j0rs 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tiresar kebjd,60c:jamx0 / and the road for the car to make the turn?

  A car is moving with a constanygt 7un wn ,l,x2,v bc999qaskt speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What isv,9nswgbuqkyx9, tcn 927a ,l the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is requ3n ) 9cb (bplax ..ukmc jhxk)7ra-qh7ired for an Olympic bobsled to negotiate a 100-m radius turn a namh7cxj h.. p k()r3b9b -7k)ulcxqat 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled h/ cn3cj8 :vrq0z u6xcgnq. kutfc9:2abl+ a: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, banked at an anglehxwc4 6 n2(rnf of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m c4m3biuw kc,hhb- mi:*4i -nu is 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 is revolving uniformly in a ho rq0ca/ph(8 gerizontal circl 8h 0gq(cea/rpe of 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 area, a race car accelerates at a uniform rate to rfjtjlfv nw3:e25qtn- 8q)l.k pov ;.a speer5)kqj;pqn:ve2. 3jwt-nol8fltv. f d of 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 consists of a proton of mass 1 ee25hyfrkf0z c rqeqrw6 )*1$1.67 \times 10^{-27} \; kg$ 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, due to bjrm5 :9rpf vz( 4g3dgthe Moon? The mass of the Moon :brmr54dj(g3zv f p9g 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 vf0.: 9kznd1gdw 6 ms kh9ixu/are moved to half of their initial distance, what is the gravitational attrackv0. z/mgk1:uhd sf ni9d6wx9tive force?

  For a spacecraft going from the Earth+ m; bj) ximo ivafqtqnm ;84l/60ekx+ toward the Sun, at what distance from the Earth will the gravitational forces due to thet+;jq/4oie q+fvanm86 l ib;mkm )x0 x 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 isfkhq,i cv;2 gbsi t4o8.v7b.a $7.4 \times 10^{22} \; kg$ 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 abo:aghf6b )rce 16rya 7zq dy/b*ve the Earth equal to the radius of the Earth. What is her acceleration due to afzc1b: 6 6agrbyydq/ )7r*hegravity?

  The radius of the Earth d1b,nlv. luk9 is R. At what distance above the Earth's surface will the akb.u1dllv9 ,n cceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface d.hlkpkw5vp-: b q;b )c;*ude equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as comp-.hpb*e ;l;bwupqv:dd ck5) k ared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, r9f 3.c(cwflxthe acceleration of gravity3fcxrl9f.(w c is $32 \; m/s^2$. 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 thvam wo9k/o (li) )5zsbe Earth. The Earth has radius r. If the object is raised to a height o)l iwvm9(sa zko)/5bof 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes fro, 7bpxkt /dz/l2-ljatm sea level to an altitude of 5000 m? (The mean radius of the tlz2al/p-7,b/kd jxt Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg /n.c -a ezsyt.is at a point 3r above the Eart. /t-ec z.yasnh's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twije1ds/h .zduvcv-so -7yv 9w -ce its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface ofvw-v-d.v1s huzy9j-esod c /7 this planet?

  During a lunar eclipsezk )9a4ka,oiw gr+;ao, the Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the S4kra gi,o9o;) zka+w aun. 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 thx3jna.sv/ygg4 :y 1by e 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/ (f/mmix(tc wdr-m) t orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean rdtxm wfmt- (m c(r/i)/adius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low c)o f 4.j.;,muj dhr9za ;y5h/tz/a.gwb lyrysircular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does ito, .ju;fa ; m54r.ya/hz /dr)9shwy bj glty.z 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 230 km above the surfaek)y 2k8 gj)c4(mxkpwce of the Earth. It is observed to have a period of (g k8x)2km)pyjcke4 w89 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 an orbital diameter of iz2x7dy4 jy 1g$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jup avk7zxq-.6fg8e/c bk iter orbits 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 plan4 cj:v l 0yq1g52 (nye .usr;-jwlbgpaet in nearly circular orbits. Moon A has orbital radius r, andy 12p -yl:4;jv(qun rcbsagg0.ej5lw 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 is i4 v3:eyxd-d1 jv z;efxrak, zce5h8x bm,:k:$7.78 \times 10^{11} \; m$ 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 Jupiteh(+nd b z)*rcmt t+kqei)q ,pjfd)4h3r 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sh q))pnd k,3*b(+tzidfq c mt4+jher)un? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)