Is it possible for an object moving with a constant speed to accelerate? Explkzkc7er4loj * )wnse *(+ hyhqp 9tk+7n0uc f6ain.nq7ucpo rk) zwly7kjhc+f*( tk+ *e 9h04nse6

  Consider a particle moving with constant speed such that its accelerc/ pjic)9 cw5/kd3fy eation of constant magnitude is always perpendiediy 3 c/cwc59/jp)f kcular to its velocity.

  An object moves in a circular path at a constant sa:wlhdq)5 cr s8 9*jbspeed. Compare the direction of the object's velocity anw5 :8* s)9 csdjhlbrqad acceleration vectors.

  When an object experiences uniform circular motion, the direction of the acce ujhh,d/ )*gb dhs 8:s;kms4w5sdu(uolerati:h g8su) uuk,s wd5s/djo( s4 b;mdh*hon is

  Consider a particle mchy30f *o4i4n uk23pe mc;h utoving with constant speed such that its acceleration of constant magnitude is alwa ukihfpm3 4 *n c3o;htc2e0yu4ys perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a crjkhw1edo: 6y -zm/1nircular path experi-ndzhj 6o 1e/1r mwk:yence?

  What force is needed to make an object mow5-c1bquv7;+ v ca/5 px rnpopve in a circle?

  When an object experiey l6pd1(wx5lmz v22uw*wkja6 nces uniform circular motion, the direction of the net forcl21m2(6wwvy* 6dualkw jx z5p e is

  A roller coaster car is on a track that forms a circular loop ilt* .8le3qgd in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is thi83.t elqgd* le minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that fo4s4qa d dxaqy7bdix1 d5g1 u/;rms a circular loop (radius = r)yqs1db4 1q/5i 4d;dxudx a7ag in the vertical plane. 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 veqd* kosncyba/v m7u0 kyc5l tr;t7) 69rtical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the for*6 yun; 79qs y7trk)a /m0kvlcb t5cdoce 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 radius vqh5eqb)/duo82 eebf -s k.v+$r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius : jna nd/oq+ *x4(sfsa z.k8qhr 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 the first tim na(/ h*sfk8sz n4x.:qo +dqaje?

  A car goes around a curve of radius r at a constantcnq8 b7nz;/huzhacx ga02 2.o speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centr;hu07o. z2acnhna2gz8/ b cqxipetal 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 radius r wixkg -z/w)o*i k3yx x6jth speed v. If the road is fri*o-wxz/y3)ik x k g6xjctionless due to ice, the 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 :bhlt uor7) .rcy z(e*xnemvnp8) 8p+ on 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 8(.o7mhtly8 rc n)+*v zb)peurn:e xpis v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track ov )xaiz *6js7is not constant, but increases upward 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?i )oz xvaj67*s

  Is it possible for an object moving arosp p(qhc /p91fund a circular path to have both centripetal and tangential ap1p9ps( /qhfc cceleration?

  The gravitational force bo;5d qk yz7*usetween two objects is proportional to

  The gravitational force between two objects is inversely xec 2 tguauk56eht *w7e/0z *x9cket7proportional to

  Two objects attract each other gravitationally. If the dist1 /ek 8)o7xjvrr ouv75k i xmo:,ulni.ance between their centekj75rm v )l /u.exvkirx7u81:o,o niors is cut in half, the gravitational force

  Two objects, with masses gyubp 8/b3q9h$m_{1}$ 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 ma10s yzj4iv dwl(:i( /r;dvke uk 9po+vsses $m_{1}$ 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 universal7 xr de+k*6 z(bdflp6b gravitation.

  Compared to its mass on the Earth, the mass of an objqi )+jk 2icu7iqap)*lep q.l9ect on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earthq ox7pb(oo,el 3:xe*z. An objecboe3x(oq ,ezp: * oxl7t of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the q+u vx80a u;-euyx-ui rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pul(kf gr p 9+d-eljrpef9v2ika+7bq /d,l of Earth's gravi+q2 ,lpgevdbp jefrfirk7 9-9/ dak(+ty?

  Suppose a satellite were orbiting the Earth just above the su1yc+uhmx k+7iyn8nl8rface. What is its cenm++y x khuc8 17nin8yltripetal acceleration?

  A hypothetical planet has a mass of half 3 qq 5(sbecjv,+y+e rvthat of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity one v+jqcby3r5s,eq (v + the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon isy d) st.dihn2pnz u8j3 +i39wd one-sixth what it is on Earth. The radius of the Moon is one-fourth that ofstinj+p h dz)dwn8d3u3 2y.9i the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet Bryyv2*cheuijebei 7j1g,q;/ *(f.il has twice the radius of planet A/j2 ;f.yh,*i*uejrge(i 7e 1bivqylc . If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twic4d* xo.o )knlje the mass of planet A. jkdnlx *oo4). If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (3svsn)zru , hu* q4yyf 5pli3a7gi/* 8ayl(earadius r) about a spherical planet (mass M). Which expression gives /5ya7a(na g 3luli3vs)4ri*euzp* 8y,syh qfthis satellite's orbital velocity?

  Satellite A has twice the mass of satel(rvan4qg3ph 1uf d-h( lite B, and rotates in the same orbit. Compare the two satellite's snuq1f3dhr (pg h-4a (vpeeds.

  A person is standing on a scale in an eleva +fvny +5oo;nbq zq5r4tor accelerating downward. Compare the readi fb;+qzqnnov54o5y r+ng on the scale to the person's true weight.

  Who was the first person to realize that the planets move in ec4gr/xjdxltx 9tf /4aqfn /,5lliptical paths arrxq x9t4/g5ja/4fcn x / d,ftlound the Sun?

  The speed of Halley's Comet, while travelg1l., ajub0hx1r rjqg sn p)) rdr+8z8ing in its elliptical orbit around the Sun,r1.g nj,8xr)hd8 +aqg1s0)rur z p ljb

  Let the average orbital radius of a planet be R. Let the orbi k xtfkky xt)*u*2b6/iprqj91tal period be T. What quantity is constant for all planets orbiting the kx1 6kuttpkx b/**2jr fy)9qi Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with (i kmfn 16l;tilas03 tthe 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 planisa0t ikllnt(;m613 fet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined /uh c w/:t1t 4ewau2vu/a5 owyas one "astronomical unit" (AU). An asteroid orbits the Sun in one-third ofv u5uwy//c2teuw ha 1: /owta4 a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. p(jrbqz v2)4a+dip b2;au /lh:jws6 n

  List the four fundamental forces in y1yzan92:ipln- y9mej klxg3r ) a0x/nature.

  An object moves with a constant speed of 30 m/s on a circular track oedza8drz;9yj) mey,.f radius 150 m. What iz e,mz8 )re;y d.y9jads the acceleration of the object?

  The maximum speed around a leve;g(h b1dk(knkl curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other dhk;nb kk(g(1factors remain unchanged.)

  What is the centripetal acceleraw4 vx3x*sq;o stion of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/s3x q;4sov *swx?

  A point on a wheel rztjpf5l095i 5yo n)vpotating at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal yo )nz5fi90vlptpj55acceleration?

  How many revolutions per minute must a circular, rotating space stati9qo .zm.p,leh 5x)yu8em/adzon of radius 1000 m rotate to produulmxdp/ 5a8,)eyqhm.o z. z e9ce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 2zli/jpdy- 4cq.rm91 vh;covk 7 3f wu250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is thevyc hqwji-2kuc/ o49fldz;vm7.p3r 1 centripetal force on the motorcycle?

  A 0.50-kg mass is attached tni3 1)1eces;jjjcp6kj :t5z s o the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can wic ekn :s;)j e1sjjicj 1563ztpthstand 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 vertical ci*u+w gz0 qx2; qdveu5frcle of radius r. At thuzd;fvwqe gu+*x 20q5e 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 t0 k,7scg4sefl.6*f a,qtl vtko a strong string and whirled in a vertical circle of radius ke *06gt kqf7cvl a.,flsts ,4r. 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 expd kvf; w.dq1nsr: /ql,eriences an acceleration of 4g when pulling out of t /w ;1,sqdv.qk :rdnlfhe dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside j, o;2sr+ciun vertical loop (in which the center of the loop is beneath him) of radius 3200 m. At thecs2;nu ,rj +oi 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 seven times his weightn5w*xs9l oygzm3u11c . What is the 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?zu mg1 yscn3*l91xw5 o

  A car traveling 20 m/s rounds an 80-m radius horizontal cur:y9nr ) 1:trq ec6tax jx-8zy5 cntc-jve with the tires on the verge of slipping. How fast can this car round a second curve of radius 3xy c1re : yq6zjn)-nj-9c: 5acxtrtt8 20 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 v8lo9tom*o;x n (7js twith a speed of 20 m/s. The centripetal force provided by friction is o;m jlvnoo s987*t xt($1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a speed of olpn vj:5)gg ro*x-0 t14 m/s. What must be the minimum coefficient ofvxn5*lp g0 :jo)g-t ro friction between the tires and the road for the car to make the turn?

  A car is moving with a constanlq*). 0gmqw r.2k yaydt 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 the.lkrdw g0q2 *mqy). ay road?

  What minimum banking anglpl hk ni6xov37d.c5/m e is required for an Olympic bobsled to negotiate a 100-m radius vnmp io7d5/hlc k 6x3.turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run poak8t5;m9 iefkfq29is 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 angle k ;c0rc/c gt4yxr+r1fof $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banxv3 :+vodn) oxpf;i 9u/x xs1rked 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. d 55ed5bxaxl v+v5m+ bzngs3 revolving uniformly in a horizontal circle of radi5gd5.l3 nv+svdxb zxmeb 5a5 +us 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 a+he:cn + ,bi1*n *k7e d:dwhrd7ohp rjccelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value in to ni:7*7heprk 1:+dr*ejdn h+, chdb whe 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 a3aw 5 j/x1yt7ykxzi-u 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 perdgs2t s e/0- :nn*f:coso woy3son standing on the Earth, due to the Moon? The mass ofon*efc2:gt/0ysso sn-3d o :w 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 masse4 lje8 h/qs5k.seft5:ty6bds s is F. If the masses are moved to half of their initial distance, what is the gravitational attractive force?dt s6 y/s lhsf:t 5ke.e485bqj

  For a spacecraft goings *a3v*gl yn+7ucqb6s from the Earth toward the Sun, at what distance from the Earth will the gravitational forces duq 7b+v 3scgsnaul**y6e 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 9j a k,2y2foajq/qn3kb3lfcb0 u d+*b$7.4 \times 10^{22} \; kg$ 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 distn9d60q/ numnm ance above the Earth equal to the radius /0n ndunm9q6mof the Earth. What is her acceleration due to gravity?

  The radius of the Earth r9j-f(tml 6 t)-hzyxjis R. At what distance above the Earth's surface will t-6f z9rjt)l- xhy(j mthe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its mldv (f+q+jx5 9irf8c surface equal to 3 times the radius of Mars.+ d +milv9 xcrfqf(85j The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000pxm;(/3mjj9/bm f mmy km from some planet's center, the acceleration of gravity ij9/ymj(;b/m3 pf mmx ms $32 \; m/s^2$. 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.,oes ygk3lh70 The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is itshyg7kol3,e 0s weight?

  By how many newtons does the ki85p *,z9kz5rm2irmn* unmv(sbj b :weight of a 100-kg person change when he goes from sea level to an ammm v(s85u* rn,2zk9kb *jz i pi5:rbnltitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a poi f tv1(.uu;dhcnt 3r above the Earth's 1u.c fh;d u(tvsurface. What is the satellite's weight?

  A spherically symmetric planet has four times the Eartk72 soj gu z:kgi0m7ikr 3e6l5h's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earthk3iozsj6kl20 im7:k u75 grge, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on theg;4h)7:ek l0 gzx zkok same line, with the Earth between the Moon and theex kh7; 4 oz)lkk0ggz: 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 t m -e-c,5cimwthe 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 circulk +s6vbg 8g7hyio xl1+ar orbit about the Earth (i.e., it just skims the surface of the Earth). What is th+h lgi7o18gxbskvy +6e 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 about the Earth (i.e., it just5nyfv3p afy9- skims the surface of the Earth). fn5y ypaf-39 vHow 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 2 f* y*d(e:xpzw30 km above the surface of the Earth. It is observed to have a period of 89 mi:f e*yxdp(wz*n. 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 o fxm j63jtp0dff4vth s/2,vb)f $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter oka7q- /v3 mguarbits 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 near+kty,88 ml)sdyxx-h 2wjp*ujxy v(p* ly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to compj8 wxkjh,p * p (s-m)y+2 v8udx*yxytllete an orbit?

  The planet Jupiter i;jb0n4ii 8f 7qkue3ofob qq(3 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 Ju huzse3j4ksl t9 kc7z3 b u53tyah;4b8piter 12 years to orbit the Sun once. What is the average distance fromh cz4bzbu3y4 t9e38khl3 ;ts7ksu5aj Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)