Is it possible for an object moving w.oh2ij s,hvc5u7c n-qith a constant speed to accelerate? Explaini vcjq,.cuso2- 5 n7hh.

  Consider a particle moving with constant speed such that its jii9w sel3- iy w;wq*5acceleration of constant magnitude is always perpendiculei;*ji il yw3w-5swq9ar to its velocity.

  An object moves in a circular path at a constant speed. Compare the direcxjhc 5kp1le0m ++ tw,e 6or-pytion of the object's velocity5+,1 h-e olrpjcx6ke+ t mpyw0 and acceleration vectors.

  When an object experiences uniform circull pkmcxm0-)9aar motion, the direction of the acceleratilp)a 09mk cm-xon is

  Consider a particle moving with constant sz3q qpq- s m4::ixc6btpeed such that its acceleration of constant ma-t zm:cq:qpb4 i 36sqxgnitude is always perpendicular to its velocity.

  What type of acceleration does an object moszbk :94jnf7 l jucwg94 wrw4hr(9,peving with constant speed in a circular path experiewkj9: 7s4her zr(fg bcn499p,j u4wlwnce?

  What force is needed to make an object gtkw+ u51x.4s65jjrmwq0 aqymove in a circle?

  When an object experiences uniform cirnd+1 w9aftt) scular motion, the direction of the net force int1 sa)9td+ wfs

  A roller coaster car is on a track :s f gqxfw, (nk:1uwc/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 valu 1n:(ux:swkgwf, / cqfe for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a traaqgv)sqwnw:gx 74n b84:2z dd-flo ,cck 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 theq:z4 8s , bo2c-:xvnwd74qng l)awdgf minimum value for its speed at that point?

  A pilot executes a vertical dive then folyevib3); 0*q*s rgy.vre,vdl lows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, ,*vi.rr3qdv*l gye; b0 ye)svthe 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 c.40abolr3ml 8cedu+ sya,f q/urve 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 ray :k*btc;j d+jdius r at a constant speed v. Then it goes around 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 t ctd:by ;*kjj+he first time?

  A car goes around a curve of radius q )y qc )xi3wlvfu1*j*r at a constant speed v. Then it goes around a curve of radius qy)iv* wc31l* xu)jf q2r 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 8o,tv8 7h ko 84 do+4n qkkvqto:nl.scaround a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can sh4c88 :qln o,v t7+os8.vkondk4ot q ktill 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 on a bobsled run arer bo+kjuph/; d3 s2/f 21k.mrids.iys 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 larger radius cur +m surp/2kbi; d.s/joidr.3h1f s2kyve?

  The banking angle in a turn on the Olympic bobsled trackm7jybyj cnzhq*.: cuq6z9 erj 1+u,, j is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then jc,j h7+:m6cez y*nq,1yq.zuu j9rjbgo lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a 2ce2-nedv7v2 fb5c y-gcq k9bcircular path to have both centripetal and tange ce9yebk-vnc 5fd72qbc 22-vgntial acceleration?

  The gravitational force between two objects is p)a .sll l7i.ll8t8 cds-t(uxwroportional to

  The gravitational force between two objects is invers/y/4)ua cgvl lely proportional to

  Two objects attract each other gravitati-v67 ke(oxy5(5q *bul)ybx 4 avllxi aonally. If the distance between their cente(x )qa y7i-e( vby lox*bkl6xauv 4l55rs is cut in half, the gravitational force

  Two objects, with masses 66; d 6ukycb;flgefv))tgm) y $m_{1}$ 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 massesjs4cel42* ch w $m_{1}$ 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 un14v-( knmigfyiversal gravitation.

  Compared to its mass on the Earth, the mass of chku63 5arft:3e w-bs an object on the Moon is

  The acceleration of gravity on the Mo 2da q-+kt8la/ewpht9c/hpo 8bv4ae y :d,br,on is one-sixth what it is on Earth. An object of dl9+h dtvbqy,er/w/ :- ,p48b aak2p tae8o hcmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket*lqqjb75dbw n,yb8r38 esxv. 3lx lf 5's weight

  A spaceship is traveling to the Moon. At what point wnlk15m+ikom 4b i zzx66+hd+is it beyond the pull of Earhiwlz 16x 4mk+k ++5mondb i6zth's gravity?

  Suppose a satellite were bmf0 yf:oqyr 2n v/59;uzkolgf e57 l2orbiting the Earth just above the surface. What is its ceuk:2f ;b0l7fol2yv/ noqye5gzm 95frntripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth mq;d3ah/uz 1xand a radius of twice that of the Earth. What is thm/ 1azh;xq 3due 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 Motj zpi 9huer 4wy/l ix-*7;xt4on is one-sixth what it is on Earth. The radius of the Moon is one-fourth tha/tz ;*ehwr7ti- puy ix94xlj4t of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same ;fey:(hc.jvn -ok;z ymyb-v i v:6 2mksurface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of plane2zjyi v-h:vk.e f(-:v k; co n;6mmbyyt B?

  Two planets have the same surface gravity, but planet B habzgcwicr67zf5rr- obp i:dr ./o7-m4s twice the mass of planet A. If planet A has radius r, what is the radius of plrc/ of rim . rdboz--6r4zbc7:w75 gpianet B?

  Consider a small sat;e c1rgxhebs9(*g0;wk3ee h iellite moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital velocgi3 xr hgw0*;beh(s9 e1e e;kcity?

  Satellite A has twice the mass of satellite B, and rotates inn0/axpgii8, r,pz0kaf3. v * x acvr:b the same orbit. Compare the 3 ,xfpv *kagrai xp,inc/: z0ra b8.v0two satellite's speeds.

  A person is standing on a scale in an elevator accecgtskwx3k -( *lerating downward. Compare the reading on the -s( wt*k3xg ckscale to the person's true weight.

  Who was the first person to realize that the planets move in elc9ey/fa , jym; *d-+ reg-yitoliptical paths around the9o-;cygj e admt- +yire/,* yf Sun?

  The speed of Halley's Comet, while trave4cm p v:z7ntv5ling in its elliptical orbit around the Sun7 vt5: 4pzcvmn,

  Let the average orbital radius of a planet be R. Let the orbital periohs: 4fuqk// jlzhak8uk *-*kvd be T. What quantity is constant for all planets orbiting the S/alzhvkh-suu8/ 4* *qjkk:kf un?

  A planet is discovered to orbit around a star in the gabi6pu/ .c4e 4ha9c dti,p/pw vlaxy 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, compared to the Earth'scu /bhe,/p6pd cp 4t4aw i9vi. orbital period?

  The average distance from the Earth to the Sun is defined as one "akz4vf .)/qz-7oula q/2ot xlostronomical unit" (AU). An aster/a-t7k.qol2voqoz z ) l4 x/ufoid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.k*1-pq)wxooa 9:w5l 9k 0fuekff yz:i

  List the four fundamental ffvv, aibe1qofv8d 8 t yh:)1w.orces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiu0uf0ssxf.z04i yaek 3 7 b4djes 150 ed7eau03s0kb4zi.0y j s 4xff m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximub6nohr*k0zz f 4,i1ro m speed around a curve with twice the radius? (Assume all other factors remain unchangedokon* ,4r1r 6f0ibzhz.)

  What is the centripetal accelerbk /wy4fyo;,l r11 wgn;y- xxsation of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 mo,s1y -g x1nkb yr4;;fxy wl/w/s?

  A point on a wheel rotating at 5.00 rev/s is locatlu47sb fz-y8al9b9b /we0iym; bmd ;ted 0.200 m from the axis. What is the centripetal acceleratiod 0ml-waz; e9ubbby74slty9/i8;f b mn?

  How many revolutions per minute must a circular, rotatingf;wvlyf5w( (qbno8x) space station of radius 1f)8 n(ox w;bvwfyl( q5000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg.vh1;qb+c zzaj fl84f2c,2lrk,dqx +m It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force o vcxqzbld4cm212; ,f k++l, 8zfrh qajn the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The syns z h+;qw7y rct,mi2.c6gp) dstem is whirled in a horizontal circular path. If the maximum tension that thet c.mzqys72 6 nhgpd)c+w,ri ; 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 ad4r c:r *h6kwfci 9dumy*:dk : strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times thdru:fr:* yc*dk:9d4 6 cwikmh e stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached td5e u88kal41am:f sdro a strong string 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 this4am1al :ddes 8 fr8u5k point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out o yxw*5 a(b hekw7vzltt afbyy04:m.(;f the dive. What is mw5vl(4y0 zb7y(a w k tx:ty*h; eb.afthe radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the vv :;l8apkj, pt:9waq/s p) ltcenter of the loop is beneath him) of radius 3200 m. At the top of his loop h: /:;wavppltp8lv jkt,)sqa9e 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 stand0o l*m mne9ys. ag1i9c+ac6igmg:- hd is about seven times his weight. What is theihymn c g.ames :*9ldi 60+o-gmg c19a minimum radius of curvature 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 with the tires on q0)iioqi5am)oso+ ( 0.qojz z56xf0i-n zoyf the verge of slipping. How fast can this car.6 ix0ifooi q(05ojia)fqzs +)qz - 5nzymoo0 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 sp8v:r 41kjorv geed of 20 m/s. The centripetal force prr4 vv1kog j8r:ovided 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 speed ofv*t1 vd*6 x3ijp4 rjpl 14 m/s. What must be the minimum coefficienpl*rt 4*p1jx v i6v3jdt of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coef, 5dy x1hqa.tmficient of friction between the tires and the road is 0.40. Wha a1x5 dhy,.mtqt 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 nf;p5/) 5iimgiyxg0c,f-r tt vegotiate a 100-m radit-ci55vt; ipg0ffxg m r),y/ius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at tgdf)-yk ayeb6 7/6wp 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 ay/n gp1wky6f.lw*;csn+rw( bn angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 vn ara+/ixrb8 n a/r/5m 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 drc/7l *d- 4wo9ysiofa string is revolving uniformly in a horizontal circle wsdlr7oo*d9 yi/c 4 f-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 carf bryho./ 9 ;wc,+oe e.hvsre+ 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 fie./.ob+9r;r,e cs ofv+ whhy ell 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 co0 dnm-d.wyq uob:s/v:8wiga l q8+)ocnsists 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 sta4 t v;ccptiki-)cu; (/nmt)u znding on the Earth, due to the Moon? Thp-tkuctv i/4z)n( c;;ut m)i ce mass 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 massmaai3sa g/zx1mm6 2dvs5u;a 2es are moved to h;dvmm2 a3a s1a2sxzamiug/5 6alf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from thxs;f0tq w:)c) aw4fe5 l2du sxe Earth toward the Sun, at what distance from the Ears 2)q:uw5f0wd ) fx;a4secxltth will the gravitational 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 is li69perpwv9g uil *9yq) 6wc*$7.4 \times 10^{22} \; kg$ 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 ay*o;s u i59eztw0ae fzdrx6 ;- distance above the Earth equal to the radius of the Earth. What tzyre ;9 u5 wzs6-eox0id*a;fis her acceleration due to gravity?

  The radius of the Earth is R*b 7eqvz)y rks5:-mh w. At what distance above the Earth's surface will the acce s*z7 e-vqmb)5yh:k wrleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a diazs sa:2b4m-v stance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration ofv: as-b42masz gravity on the surface of Mars, is

  At a distance of 14000 km from some planet57g: enadvvpz )knptd 850 o)j's center, the acceleration of gravity is dpkz o) e5:jd05 vnnag8pvt7) $32 \; m/s^2$. 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 radiua32bpo5: tfb l iek9t/s r. If the object is raised to a height of 3r above the Earth's surfa/b5ft:3tk2 iolb9pe ace, what is its weight?

  By how many newtons does the weight of a 100-kg person change wsmrsu l / g6,+pt-ga2shen he goes from sea level to an altitude of 5000 m? (The mean radius of the + 6lm,ga-2susstrpg /Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r abog8uadba,a( / gve the Earth's surfaceda bgu 8g,a(a/. What is the satellite's weight?

  A spherically symmetric planet has four tim ab3 zm9ia7sf* *vsca8es the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 Nsa7a3f8bzcv 9 ai**sm on the surface of the 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 same line- )yp*qj) yxad, with the Earth between pxy )ja- *d)qythe 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 transportebuhflgp4 s*x d:kce.c /t23)cd 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 (eq m;s3s c kmdtj2.68ci.e., it just skims the surface of the Earth). What is the spk .s t d268c3sq;jecmmeed of the satellite? (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., it just skims thex9nqd);vmy m - surface ) nmd-qy;x9mvof 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 orbip:ua7 +d*v yvbt 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the va p: 7duy+vb*mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, ha sn* x3z4-q p5eu3a pj2q6 e-alm9gzkxs 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 planet wiq,8lcf9qbbt.a-ht 8l th 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 orbital rad8j.b(g 2 0rqf9 )9dvtu cceudwius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does itwqdg)0cv (9urbe.8dc92 uj f t take moon B to complete an orbit?

  The planet Jupiter isx7w6l5: pds as $7.78 \times 10^{11} \; m$ 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 orub e0y a0u*:7omgs4gr 7 pp9lhbit the Sun once. What is the average distance from Jupiter to the Suuegr97by :p4sa7uomp h *0l0gn? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)