Is it possible for an object moving with a constant speed to acce 0qq z9joiq1e-lerate? Explain9 oq1- zeqijq0.

  Consider a particle moving with constant speed jgmcmwm (:e aj,arp 56 *srp63such that its acceleration of constant magnitude is always perpendicular to its veloc je,*6w m(:cr amp3majrp65sgity.

  An object moves in a circular path at a constant speed. Compare the direction odm thb,d e66 lyqb:3/of the object's velocityqyb:3l the 6b/,md6od and acceleration vectors.

  When an object experiences uniform circulam lz 1:s;dh+wxr motion, the direction of the acceleration isx1zlmsd;h + w:

  Consider a particle moving with constant speed such that its acceleration of cbx 2jyd( +p-(lcu9btconstant magnitude is always perpendicl9jcpd( x u bty+-2b(cular to its velocity.

  What type of acceleration does an object moving with constant j3h2v ,9vsdtb speed in a circular path expeb9v hv2ds,tj3rience?

  What force is needed to moylj: 6gy6,t gake an object move in a circle?

  When an object experiences uniform circular motion, the direction 38m/ ;l :j tjscie7gbcof the net forcejc8/i: g slt37bc;me j is

  A roller coaster car is ono+,vs :rfbk z5 a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with tvsrb zfok,5:+rack at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass m*z qzvv+sy71udza:3 = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at t+u 3*zz aqsz dvm7vy1:he 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-circular arc until nr g )da9va/6hp*qydie98;kcit is going straight up. Just as the plane is at its lowes/9pc ;)rn k*6eqi vdh98agyadt 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 radi 2(rz dx)4,;xx(c / pnxlorwbxus $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve(tw c8i7; 0i uh3olafu of radius r at a constant speed v. Then it goes around the same curvulthuia ;0iw8f(37c o e 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 time?

  A car goes around a curve of radius r at a constant spe80dcic7 11 akbgih +cued v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as i+gubc8a ik1c017 dch it goes around the second curve, compared to the first?

  A car of mass m goes around a bank; jjbh634xk 9eabi itq *p(y.ued curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontalb;upxjt9 i(3 4*hyj kiqe6a b. component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled rukol/p/bzgy +f 9k) -tkn 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 safe speed on the largerz /kokpg k9-t+)fl y/b radius curve?

  The banking angle in a turn :crwozar (wia 6e /hw078y0rpon the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming outa/rripc w6 oz:7wryah0ew0 8( of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to ju bl;vv36)i 65kpywv e7 fyjyun39b/ have both centripetal and taniy 76newubk /y;l)jp56 yvj v 9uf3v3bgential acceleration?

  The gravitational force betwee2up- njhwjup1u u 880w2l/wz on two objects is proportional to

  The gravitational force between two objects qnxk 3d;f) xf ihj0+8/y; yssiis inversely proportional to

  Two objects attract each other gravva.-mm 6mo,g fitationally. If the distance between their centers is cut in half, the gravitational forcv m- amo6fg.m,e

  Two objects, with masses+u9 xn :*:lgofq ojft8 $m_{1}$ 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 masse jcg;cr nif( l1oyl.-0uz5ns ,s $m_{1}$ 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 uc4 2rcc4v6us5yf q *sdniversal gravitation.

  Compared to its mass on the Earth, the mass of an objessfw/gzee . kw61xqv)s2q5 m;ct on the Moon is

  The acceleration of gravity on the Moon is one-sixt h)k*+e-v ijmgh what it is on Earth. An objgmjv-e h+ki) *ect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'szzjf- 33en (s4 1u9scxjjhs4t surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point:vb:2tsy*l. , t) lsev 1kthlx is it beyond the pull of Earth's g:by l1lht:xt ,*evsv t .s)k2lravity?

  Suppose a satellite were orbiting the Earth just above t6n7n agl/(t x-5iysz6)v e ojvhe surface. What is its centrinngi6e a(sl/ 5v- xyt)oz7jv6 petal acceleration?

  A hypothetical planet has a mass of half that of the fsrm4i k(t g8ugiw1z*q3v5xr v ad./.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 due tv i5g* z1mi.kawu grs/t4x 3(rqv8df.o gravity at the Earth?

  The acceleration of gravity on thea j-mb0u+w vnc 9*2 kfsgh3,ry 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 mass compared toa3 u2mf0rwyn v-b9* g,hk+csj the Earth's?

  Two planets have the same surface gravity, but planet B has twiceo, qg 88ec2 yuclcr215ub rzyc),n5tb the radius of planet A. If planet A h ccb8,5 oytcez21 )c,5r2b8u nuglrq yas mass m, what is the mass of planet B?

  Two planets have the samq+ 4m./:z64 ayv x1vipbgd xxue surface gravity, but planet B has twice the mass of planet A. If planet A has z6i14ux+mg pva.qb:xvyd 4x/radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbitr;m+ d1s2aveb di *0g3fqoz.rix o2w7 (radius r) about a spherical planet (mass M). Which expression g0rszw;i2g1e* 7b2 qv mxod3fiar. d+o ives this satellite's orbital velocity?

  Satellite A has twice vo+gv/r mnq4nie7 ,6q the mass of satellite B, and rotates in the same orbit. Comr /7,vvnqq6+mne4 oigpare the two satellite's speeds.

  A person is standing on a sc:1y v+c/ fbyvk fhr.o6ale in an elevator accelerating downward. Compare the reading on the scale t:. 1ff/obvy k+6cyhv ro the person's true weight.

  Who was the first person to realize th2cx u8v01kx wfat the planets move in elliptical paths around tfwkx v x108u2che Sun?

  The speed of Halley's Comet, while traveling in its ellipticknsctqoeukblv/ioyn(*017g8w3( 48c ffi7 r al orbit around the ioe wo *gc k1 c0y8 (v7/n3qfniuk7(sbfl4rt8Sun,

  Let the average orbital radius of a planet be R. Let the orbital period be T. y a -0tzm/w7yy+xuil* What quantity is constant for all planets orbiting the Suniy* lm 07wyx/ yuz-at+?

  A planet is discovered to orbit around a star in t;d z6ffu0;em 2)8ujoj j *fb*assc .nhhe 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 revd.* s s)u 6;noeuc8jj2 fa hfb;m0fzj*olution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun )ygo7+ x4ns6ld; y xzyis defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. y7sxo;4yy xn)6g z+ldWhat is the asteroid's average distance from the Sun?

State Kepler's laws.6tg 6, 5sr:z-d89+f zjknlf sd*ayvkq

  List the four fundamental forces in na7u hnnxo+1cg c71-z vyture.

  An object moves with a constant speed of 30 m/s on a circular trm ntl3clrnbe.je.1 / .ack of radius 150 m. Wham .1n/n.l ej teb.lcr3t is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maxit0jx gl0 b:oft7.qw e f9ng7z8mum speed around a curve with twice the radius? (Assume all othg 8q no:xwjz0f 97 lg.bt0etf7er factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a b)4u;/ vn tyopc*dm93gef8f2pi r6kjb icycle wheel of diameter 70 cm;ui /p3k *4ydnoce g tjb6vf )98frp2m when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 7wpir:fulxmh,yc: 53 m from the axis. What is the centripetal a: iym l p5c,7wfu:r3hxcceleration?

  How many revolutions per minute must a circular, rotating a5vgeqo x*pr)3q3 zf*ixk0i1 space station of radius 1000 m rotate to produce an artificial gravity of ) irp*q3*kqxv5 iego3zf x a01$9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.o 9i48v 6*n25 mac.xlf0ixxl xas; pjk7 m radius turn at 96.5 km/h. What is the centrip;f. 6x0i*4l 2 5l aix8jnx sckaxvmo9petal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system iskn0xj+dpy:/ habc48m0/ mwrj,ri l )r whirled in a horizontal circular path. If the maximum tension that the string can withstand is 35i 8 yhkdnl:w)xrc ,rp j /ja0+m0r4m/b0 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 whi/sz myne7t/ )t5 zb)fgrled in a vertical circle of radius r. At the exact to tb)y tmg/)7s f/nz5ezp 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, i+ 0ozraigf.685z nsf,,lvb eo s attached to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the .o er+ib,60ffaz,8 nz slogv5string 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 an aci( pdl:r(dd k7celeration of 4g when pulling out of the drd((7di p: dlkive. What 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 the loo 5v/d y*v chdos rt1pkw 48vidt22+nn6p is beneath him) of radius 3200 m. At the to21i ont v r/hdwyk2n*+68 dp5ts v4cvdp 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 times his weightwn0o ins163ozb8w b5 fe1z a(t. What is the minimum radius of curvat ooen(0w1anzif8w z1s6t35 bbure that a jet 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 horizontal curve wi6mtv ayoj3a41e t7 (mm: sc8ovth the tires on the verge 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 eacha4ct:tmay8m 37ejv(61oos vm road surface.)

  A car is negotiating a flat curvepd58qov)o *wj of radius 50 m with a speed of 20 m/s. The centripetal force provided by friction iwj oqo*p85 dv)s $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m q4rp gf.x 6sxpdq(q(.at a speed of 14 m/s. What must be the minimum coefficient of friction between (.(pqg.srxd64qq f x pthe tires and the road for the car to make the turn?

  A car is moving with a constant speed v aro-zd(az) p/ 4qwf*6lsy:2 pllmjh.ttwund a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius:wq-lpt/ 2tzyd.h( a* pls) mwl64zjf of the curve if the car is to stay on the road?

  What minimum banking angle is required for an7iu q 3:c,edwu Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore friction.iwqud e,cu 37:)

  A horizontal curve on a bobsled run is bankfvt0k6cr0 -bced 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, b7s* gdcaskon3k,f9 -kw*: gzkanked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80w+wnx a6,rv(khj.zl9 m 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 revolxwndl:n ,jua we)cb29-6xna*+ wf+deving uniformly in a horizontal circle of radius 0.-x, d+d6nnl+jw:en 2wb *auewac9)fx500
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 d la-.j(hz./eyr,9ty3u dz iothe pit area, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only . (h.ido/3ze lt y-jruay9,z dfill 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 masstj *md+9loqc2 $1.67 \times 10^{-27} \; kg$ 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 Eaa6hk 9+ uu-zh uij,sk/rth, due to the Moon? The mass of tk/uh hzasukji +,69u-he 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 +5w8q(r+b u-k 8sayjq oqfta)zl :/r h*)yik mare moved to ha* b5ul+( i+jkt)z- 8 qrs)a:khayw qo ymr8q/flf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth tog4 crfwf 8**c0 qqcw2rward the Sun, at what distance from the Earth will the gravitational *4 8cr0fcf2rw q*qcwg 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 Moonbfsm6yrvyblp-(q+4 eid0 r7-tqxds1 i32 o-d is $7.4 \times 10^{22} \; kg$ 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 equk twdie 5. 5troaj:m27al to the radius of the Earth. What is her aiejrw52mt. d 7to :k5acceleration due to gravity?

  The radius of the Eart -u/t7a1 /wwhvvgd,f vh is R. At what distance above the Earth's surface will the acceleration ofhv ,uwvdvgt/ /a1-7fw gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at5x.xr owq3. lt*i h ;uzav5pb/ a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compai zv; b/5 qt*xrhl.ao.xwup53red to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, t 3t;jd+v+ */ vcn-b7p.oeh*iwflyd ughe acceleration of gravity il pu g3jcd7dy-.b*ew; nhvot +*/vif+s $32 \; m/s^2$. 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 r. Ifi6q:, s2f1w sj0 twpym th w06ftssw j2m: p1y,iqe object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of 2g6dcg eue11;w).bbmwp 5mot a 100-kg person change when he goes from sea level to.; dte6 m)g5m 1wp2cogebw1ub 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 seo 73slr-).q zvo6i cof mass 100 kg is at a point 3r above the Ea).ozqcl6os ev-37risrth's surface. What is the satellite's weight?

  A spherically symmetric planet has four timerjmit q5v u9mch r86kgxu5 +z0a2.g:bs 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 s+0 gkzxv.im a 8 6m5hrqcu5:rgub t9j2urface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on ther8amh.n0x k/ka- 6n cn same line, with tkc xranhkm -.8/n 6n0ahe 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 the Moon. 8mqn +6ne-q p0mkc4/n6txtqi
(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 circxko1 /6 er0u1kjzl+cs hs.6h nular orbit about the Earth (i.e., it just skims the surface of the Earth). Whar0zncss ox16hl +.ujh k6/ke 1t 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 mu sep6-f* g sb48kc8rorbit about the Earth (i.e., it just skims the surface of8um8f esp -4 bg6rs*ck the 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 230 km above the surface of the Earth.oj y5s7;qmn 4p It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth n5myq s7p 4;ojis $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of it mrioo(7lc5d by:/d(b*hl - $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with +k8c:gm n s1rh-m*br5fnm2 poa radius of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a plane (gc d-4i3 z9o.zwm8l;gig/ucal-vtvt in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. c mo9zc8 4v;. -ud t( -/alvgigg3lwziHow long does it take moon B to complete an orbit?

  The planet Jupiter isvhyy )9h wcm2( $7.78 \times 10^{11} \; m$ 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 Sunpu7b 9u- fxtrk3)br4 r once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Suu4brb9 pfu)3- rx7 trkn is $1.5 \times 10^{11} \; m$.)