Is it possible for an objectk(k8r68c x2uljwde 9y moving with a constant speed to accelerate? Explai2kyejckd r(xw8698ul n.

  Consider a particle moving with constant speed such that its acceleration ofa-9 i)fnr55 saafk:t u constant magnitude is always perpendicular to its- tinf 59:raak5au s)f velocity.

  An object moves in a circular path p.8p, t ye dk.fexqf75at a constant speed. Compare the direction of the object's velpkxf. .7fq y5 pt,ed8eocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the accele 3mfygch2f 81n38g fn21h ymcfration is

  Consider a particle movinqnrr7owl9atn7:i 5 cq*:jx 5ng with constant speed such that its acceleration of constant magnitude is always *nq on:57:9l tnxrrcijq5a w7 perpendicular to its velocity.

  What type of acceleration c.+im.bq h-je( ddai* does an object moving with constant speed in a circular pat*. +-.idb (aqmchjd ieh experience?

  What force is needed to make anvffga,p/ 43x(ngl0my nu0z0m object move in a circle?

  When an object experiences uniform circular motion, the direc yts( 5:mvgk*1mk,j kftion of the net force i(m5j g s ,y1kvftmk:*ks

  A roller coaster car o8 emv d um-cp7y 9d c.w(s 2j6rgz-;a9wp4qgsis on a track that forms a circular loop in 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 centripejr.u4d(9s;6zpg cp9os7m -dcqygwm2e8 va-wtal acceleration at this point?

  A roller coaster car (mass = M) ise/w- a8 hxdc zazyu(9- on a track that forms a circular loop (radius = r) in the vertical /z wc--daz(8xah y9u eplane. If the car is to just maintain contact with 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 then follows a semi-circularrl :ot,+v tz/g24 ,ht0ac5 xz ,dgzowb arc until it is going straight up. Just as the plane is at its lowest poin:w/c0zttzg a,+t4xh5 z2rod, gvo b,lt, 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 jo p/rl,os)1 fpa:yu7 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. 07l.p.a1cud qj/6nbsn bc.z t Then it goes around the same curve at half of the original speed. What is the centripetalbndq/u.snpz 6 7ta j.l. bc01c 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 co0wte:k 6e5 zsonstant speed v. Then it goes around a curve of radius 2r at speed 2v. What i:o0 6tkwe 5eszs 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 3iy mya0( r5hcof radius r with speed v. If the road is frictionless due to ice, th( 5 r3aihcm0yye car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves , j2zvh;jy( gjon a bobsled 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 radius curve is v. What,vhj z(;2yjgj is the safe speed on the larger radius curve?

  The banking angle in a tuo3 qob/emz*+7e/d gio n u+5cern on the Olympic bobsled track is not constant, but increases uz/+ ogmb*oe5c+e un7/o3eqdi pward 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 moving around a c5hf,r w (w+pa( jvft4qhy)hqe x; og5*ircular path to have both centripetah)v ,e;fhpro5(aqh tj(*w+g4 qxw5yf l and tangential acceleration?

  The gravitational force between two obj;nx/jq8gbn * lects is proportional to

  The gravitational force betwoji+m0 akxhfs cl6 m -(475cqieen two objects is inversely proportional to

  Two objects attract each other wc.cz x(bf-2pgravitationally. If the distance between their centers is cut .c(bz xpw- c2fin half, the gravitational force

  Two objects, with mas xcl 0)fk+px3hpo(w 6mo: hkc2ses $m_{1}$ 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 masse8 n(av *o,ihjes $m_{1}$ 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 gravit)hcd5pk o.s0 kation.

  Compared to its mass on the Earth, the mass o46awb xgm+ez 4f an object on the Moon is

  The acceleration of gravity on the Moo 8wv1uui *p d1tjy8,vvn is one-sixth what it is on Earth. An object of t*w8p y1 u ju1,vivv8dmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from g6fie: no *cz/53wybxthe Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyonja+i+*2m n8cr*n+oi hrtbx0y d the pull of Earth' ro +hc+tjry2m 80axn*+inb*i s gravity?

  Suppose a satellite were orbiting 725oys: fmivsyjo72 y*w p,xs(95ur(ig q tp athe Earth just above the surface. What is its centripetal awgoy2rvsjm*ou( psi7ys9 5( f5,7t xq2p:y iacceleration?

  A hypothetical planet has a mass of half tf+uaq6 t8 57 ki )9nlfwdq2 yi8*fegkdhat of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the p* kfif8976f) wegdaqy58kuli + dq2tnlanet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gxhpd 2)/;2qormfoq /q ravity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. )qohdp2//mr; q2xo qf What is the Moon's mass compared to the Earth's?

  Two planets have the same sur u+cvosi xci:f 7t,7t,face gravity, but planet B has twice the radius of planet A. Ifv soi cxt+7utf c,,i:7 planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but plane-a xb, m5.rdgbt B has twice the mass of planet A. If planet A has radius r, what is the radius of pmbxr gba -,5d.lanet B?

  Consider a small satellite moving in a circular orz4 2 5 1l27hwszzc,pnko /bofrbit (radius r) about a spherical planet (map ,f27l/sk n z5hoobrzzc2w41ss M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and ro oc 9 imjmtk54axo76,htates in the same orbit. Compare the ,oh ma9mi ck j56t7xo4two satellite's speeds.

  A person is standing on a scale in an elevator accelerat*ji7ut q;dzi59a0s ccing downward. Compare the reading on the scale to the perscdquj;0i 7c z5i9 at*son's true weight.

  Who was the first person toc:iq-7bckpifbq3x8c g j8.* dsf3 uv1 realize that the planets move in elliptical paths arouncuxk ig-8dpffbjq 1qb: 8iv*cs3 .3c 7d the Sun?

  The speed of Halley's Comet, while traveling in its elliptical087f oi j62o, pcvacwb orbit around the Sun,oia ,wo80v7f bpjc62c

  Let the average orbital radius of a planet be R. Let the orba-x4 ax+cucc8ital period be T. What quantity is constancc+x u-ca8ax4 t for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with thekbnfvhi4yr qw:d6j.i3v(1r6e 6z,uy same orbi4r6ey3 i rhfdk1j:b 6z wi.( 6vy,nuqvtal 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, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "hluzdv5iw*v *;vf* v: astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the *vzui fl v5**dhv;w:v asteroid's average distance from the Sun?

State Kepler's laws.v5;)d2 1y2rvhelxia i

  List the four fundamental fs(5t1* l)r q;s ,: ro8wsji lbu8oiuyvorces in nature.

  An object moves with a constant speed of 30 m/s on a ci+ us(lxg- 5ndtrcular track of radius 150 m. Whatu 5dt( +nlgs-x is the acceleration of the object?

  The maximum speed around a level curve 4o zb2k 8hvj6his 30.0 km/h. What is the maximum speed around a curve with twice thevh628 ok bz4hj radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicyclel qzyw2. ea+nabj )a 3k/k:km. wheel oqay3k en:a.b jk. + /zla)mw2kf diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is lo cw 2;w0bm vq+8iynlug+j*jqw pk 75/mcated 0.200 m from the axis. What is the centripetyimwq unwc gj;20 5v7lk q8+m+wjb/*pal acceleration?

  How many revolutions per minute must a ci9y vntn9e+ami q 7(mr7rcular, rotating space station of radius 1000 m rotate to produce an arin nevmqm9ay+(t977r tificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 slboklh-dhg:8 3tafj hb;.g(mu ) c /9kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the m ggmjb8u.3bl-9hlh /dtkf :(ch)a ;osotorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whir0icj6 z(av4g qled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mas4viz6jqa0g( cs if the string is not to break?

  A stone, of mass m, is attached to a strong string and g+ emo6f6, i616urjlhvrhhot2t v- y1whirled in a vertical circle 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 1uft2rhtgo6,rov6yev-+ 1 hljimh 6 6 is given by

  A stone, of mass m, is attache ;h tq2tt7gs3td to a strong string and whirled in a vertical cirt7gs ;3tttq h2cle 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 epn l(u7m6-axta ,hvh 3xperiences an acceleration of 4g when pulling out of the dive. Whha tul 3(vph76x- ,amnat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of .n6bh 0c )uzmw3q ujb:the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with onl )mqbw.h zbc6n :ju03uy one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven timj4uy*k ;q:phc):s1slbea( kr es his weight. What is the minimum radius of curvature that a jet plane's pil pbaerss ;:u) :h(1c4ljk*y kqot, 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 horizontal curve q od *-jech:f3fw32acwith the tires on the verghd f2 o3 -3:qcjfew*ace of slipping. 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 speed of 20 m/s. p90vn nrqud 1uy71z4abf3rgok8. 1 bmThe centunq9pay3f0b1k 8n d .gmo4v b1r zu71rripetal force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a b(l+*,qo/vhq i7uzf hspeed of 14 m/s. What must be the minimum coefficient of frictih z+,/qho(*iv quf7lb on between the tires and the road for the car to make the turn?

  A car is moving with a constmhurj232 f)j n6gu 8qqant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on thm6 u3qfh j2jg82)ur qne road?

  What minimum banking angle is requ h*ii( mc+z0xaired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frict+ci* zaxh0 im(ion.)

  A horizontal curve on a bok :t: xc6u 9.4lbonsisbsled 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 radiusk:xy-vi 4bg (y d9y/lq 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ba9a0c/ kh yf.0g4ilzekduko: 3nked 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 strin5 uoz q*lj1ywv: y1r,f9 gj2kl.x*esc g is revolving uniformly in a horizontal circle of radill1uz vr qj.c*5fo g yyk1ws,9:j e*2xus 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 unifor;xs)q*+ dwrga m rate to a speed of 45 m/s in 15 s, moving on a circulawr )qdx;s +g*ar 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 5x3v. hzydts5of 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 oxbyt 601 6xrb pq,hh l4cja)c/n the Earth, due to the Moon? The mass of the)l hqp6b y ,1/h4xba6cj0 trcx Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractik2h06bnk mk7 3ks3xcvve force between two masses is F. If the masses are moved to hbv 73kmhk2kcs 3 xnk06alf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at rvw6e*6 z8fv b9m wk1 c:x:kxoc lf/0nwhat distance from the Earth will the grav*c f109 vcokb:mr:xznvw wxek8/ l6f6itational 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 isgat(p6+ej1 4elphft-7z4dxl k;x. j s $7.4 \times 10^{22} \; kg$ 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 i pu9w4yfkv 1af*+w, h6+rlx ba distance above the Earth equal to the radius of the Earth. What is her acceleration due to gravity?a1f + 9,+r fhwkxbp 6vuy4*liw

  The radius of the Earth is R. At what distance above the Earth's surface willns g yn/tt2)y8 the acceleration of/yn2s gytt8n) gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfacel viblkim+g,cinc9(q 7 i z5p; 34rb/o equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the accelevklq5/ i,onc4m +zcbp3 7l9iig(ibr ;ration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planb )*vgyvcifzy(1 . gq7et's center, the acceleration of gravityv7zyqfyg(b1 cgiv . *) 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 surface8m5 wqemf iefi/ij4 g).oi 0t3 of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is i8/qjfi0woi4.3 mmi) e5fegt i ts weight?

  By how many newtons does the web30deps0 0 80xa6gnsiinc* /6lzdgub ight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of lud6*pe0g0xib0d 0 8 inc gz6nsas3b/the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r+k ye,-ahhxh8 . A satellite of mass 100 kg is at a point 3r above the Earth's surface. What is thk-eax8+ hy,hh e satellite's weight?

  A spherically symmetric planet has four timfwz 92xo x10pq ogy .-ubm3t;nes the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surfax-z u;qm2tgnw9oby 3po10 xf.ce of this planet?

  During a lunar eclipse, the Moon, Earth, andli n ewhj1 k866sf9+rk Sun all lie on the same line, with th 69sjik+ w6lk8erf1 hne 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 transporgd n ah..sga75an srs9ghg,6 6ted to the 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 about the Earth (i.e., t/fsc th 850ulit just skims the surface of the Earth). What is the speed of the satf/u5ch08 l sttellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low cic )vlt )ru81fhrcular orbit about the Earth (i.e., it just skims the surface of the Earth). How long doest81vr c)l)huf 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 230 km abovm c r62 /sxua6u4h9igge the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth?92cxg uhg6s6r/aiu 4 m (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, hfc unepci6 a/de;lojp yn/8 ec127-n )as 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 orbits the po7k/v0- 6 qsf,dz pkjclanet 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 circular orbits. Moon A has orbamfy w rp-d56a2 2js0wital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon Bw5ap 0am2fsyd- 2j6 rw to complete an orbit?

  The planet Jupiter is w 69;br arw8vl(ryn)j $7.78 \times 10^{11} \; m$ 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 averx ua.+m(0ylj xage distance from Jup.+uayjl(x m0x iter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)