Is it possible for an mzb5ffge9y4;dui/,z 0ow kx- object moving with a constant speed to accelerate? Explain.i/ub;z z-, ykxf95wge4m o0 df

  Consider a particle moving with constantq3,+7 hrfrb:v)6ekeay/ xezt speed such that its acceleration of constant magnitudhx+fkrzq:a 3,erv6e) et/b y7e is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare flls.fv5 v t7yv,:0 idthe direction of the object's velocity and acceid :f7v0y.tfs ,v5lvlleration vectors.

  When an object experiences uniform circular moticbu h5sk7y) .1k6y bsq7igzh0on, the direction of the accelerati5hussy. 701 h)kck 6b yqz7gbion is

  Consider a particle moving with constant speed such that its acceleratxboe1ty9 di0ap)+ y 1pion of constant magnitude is alwaysdb py9t1)epx1oaiy0+ perpendicular to its velocity.

  What type of acceleration does an object moving with p,aabkc 97dlh7t*kz3 constant speed in a circular path experil7h,3cd*9ka ap7b zk tence?

  What force is needed to make an object movi- a*o12xbrue1rt vd3e in a circle?

  When an object experiences uniform circular motion, the direction of the net fze vk0ekx k,6m2alq02s k6bj;orce ,sx kekbj0qmk2a;2k e6vz 60lis

  A roller coaster car is on ;ehrvciw )y91ij -8ctp7q5ln a track that forms a circular loop in the vertical plane. If the car is to just maintaw- 9 1tcrqyiphi7nlejcv 8)5;in contact with track at 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* pvt2v** w(cbm7yud c:y46p t vfsu;f 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 the mcps7wfm6vd4c uvvtt*:2; ( yubp**fyinimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semqz69hjk/qa4 t0t,fpub 77zmbi-circular arc until it is going straight up. Just as the plane is at its low79pth/ f qaz0zmt647 qjbbuk,est 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 bq tf(y27 ;.hqstw j4i3a 4jliof 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 dr kd5++(xna4a2( cl0ps1bai sm aduv9+u :faat 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, compared1 a vs0(4praald+n 2+fuia(+uxbsdk59cm:da to the first time?

  A car goes around a curve of radius r at a constant speed v. Theny 8yjp 4ahr6a,mkffw2e7ik 2 9 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 the aki769 p,4 2ffea28ykyw jhrmfirst?

  A car of mass m goes around a banked curve orwl t0,y64kivm 4d jx5zw+fs+f radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on th zwk+t0 5lvj, w4isx y+6r4dmfe car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at thc je (,j82j vahees;y0e7e;h we same angle, but one has twice t8yhj2,eehejv 7esw j( aec;;0 he 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 curve?

  The banking angle in a turn on the Olym(vghqm+x+w- z7l5yk wn : zno.pic 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 out of thwg (qwm ln hz:+-zxy 5ovk7.+ne turn. Why do they do this?

  Is it possible for asx9 wvgetn ka 4/t4y+;n object moving around a circular path to have both centripetal and tangential accelera 4t/9k;gsv+tex4w ynation?

  The gravitational force between twe d0) 74nmqrlcd j./0k hsgv*uo objects is proportional to

  The gravitational force between twoo:xmyy(2l :d) ij i,rm objects is inversely proportional to

  Two objects attract each other gravitationally. If the diixiap zo ,gx5x,;4z0dstance between their centers is cut in half, the gravitati4,oaixgpd5 0zxz; , ixonal force

  Two objects, with masw3 d k 56j6g0vz*vkpze8oqla+ ses $m_{1}$ 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 ma/ kt1eq0*i:ldvk ; xoufy -r*lsses $m_{1}$ 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 univers 0h0dq0kd08fdn *oq bbal gravitation.

  Compared to its mass on the Earth, twb(4.tj4 znbfhe mass of an object on the Moon is

  The acceleration of gravity on the Moon is one k1szp2s1ng3 c-sixth what it is on Earth. An obje pgnsc11sk2 z3ct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, th + .o;7un ,spvb1ifqvle rocket's weight

  A spaceship is traveling to the Moon. At what64xykyk54 ucm point is it beyond the pull of Earth's gravykc546y x4 kmuity?

  Suppose a satellite were orbiting the Eylx-pc8fg8t bje+ 9z2z xe*3xarth just above the surface. What is its centripetal acceleratixfx-3eb xj pz t8e cz+92yg*l8on?

  A hypothetical planet has a mass of half that of the Earth and a radius obncw xtuzdb14 ;x 2xn70(*k zqf twice that of thznzxxdx70b ( ut;q bnwkc14*2 e 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 xgovwj /c*+v mjn*den6c6dt1.m/)p wMoon is one-sixth what it is on Earth. The radius of the Mooc/v vdpnw6)6wxogm +cej.jn1tm** /dn is 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 pl i jrgob.pa8 0y0j(1lfanet B has twice the radius of planet A. If planet A has m 0oaj ypr1fi8(.jlb0 gass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice n(2wx)5vl lpbthe mass of planet A. If planet A has radius r, what inwp5l lvb) (2xs the radius of planet B?

  Consider a small satellite moving in a circula n3,7qu owgjvp orw1h+)craima86m5,r orbit (radius r) about a spherical planet (mass M). Which expression gives qw+m8awin35 pou h oa6mj1 ,,)rgrv7c this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, a,z .xl+y;5dml 6gfeoo nd rotates in the same orbit. Compare the two satellite's d5g,+ yl.o;leom6x fzspeeds.

  A person is standing on a scale in an elevator accelerating downward+evctzn;bmww78 3d 2fcxk ek6ojb87 ; . Compare the reading on the scale to the pee;v27w b+e k3n 6f7 bokcw88mx;zjt cdrson's true weight.

  Who was the first person to realize that the planets move sc )ifmk/n0rwx-1qa3 in elliptical paths around tha mk31inw/ rsx-f)q0c e Sun?

  The speed of Halley's dz.ni ra;-q k3Comet, while traveling in its elliptical orbit around the Sa3dq . z;-ikrnun,

  Let the average orbital radius of a planet be R. Let the orfcztx8nbhv 2j1l+9c18/ u z lbbital period be T. What quantity is constant for all planets orbiting2z lxbv l91/b8jcu 1zfnct+8h the Sun?

  A planet is discoveredci6dfsbz .tg (3gi q4x6df4t) to orbit around a star in the 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 pers6g4(gf4d f xttibc) i 6.dq3ziod of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance fro)0j;8oeax b uhm the Earth to the Sun is defined as one "astronomical uni; ohb80jxeua)t" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.*n3 o5hy,txq p

  List the four fundamental forces(v 2m1i l:pse ;yzcc5j in nature.

  An object moves with a constant speed of 30 m/s on a circular track ofzehkjujtjdi29xs 9haw-k- (+xh.e,2 radius 150 m. What is the acceleration of the ob -xhz jkd,he2(t9k+xaw e9j-usi h.j 2ject?

  The maximum speed around a level curve is 30.0 km/h. What is the 05b4:pzkndibx k -c4 emaximum speed around a curve with twice the radius? (Assume all other factors rem0:5kdx -biekcz44p nbain unchanged.)

  What is the centripetal acceleration of a point on:1 t;icw em1ei*h;ubc the perimeter of a bicycle wheel of diameter 70eb* w1ct; :u;1mehici cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from 9 d/jkrzo ,b s8jc94pvthe axis. What is the centripetal a8z r v9o94kp jj/,csbdcceleration?

  How many revolutions per minute must a circular, rotating space station of radiu30 v-blst dpb+s 1000 m rotate to pro s3bd-+pv0t blduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn ,t6j14ey fguc at 96.5 km/h. What is the cent6 fuj egyc14,tripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of;r/lj 4lox lc/)vi 7xf a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maxixv jrll4/c/7l x ;i)fomum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong str fl65)ur82 p fdwwym8sing and whirled in a vertical circle of ra62 wd5srlu8 )m8p yfwfdius 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 to a strong string and whirled in a4hma4z;u 2ckpl :.rptf.jg/a vertical cira;4f / 4pz2.carphtum j lg:.kcle 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 experiences an acceleration of 4g when pulling onw**zqf ej3r ,ut of the rqn3f we *,zj*dive. 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 d.+.4 pz ulk8lp8rfs;i 3)f,lmur w aythe loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with on).a8r+lldf8ryuf spup3 m,ik;4 z. wlly one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is,62c +oqiuub kinv 6n1 about seven times his weight. What is theqck+i vun u 6o,n612bi 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 horizohfmqo*x jmbv:2nr)o4rzev4q dn/ 4; /ntal curve with 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 each road surface./f b:vm44qnz)o hxv n2j*qrm 4;do re/)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 mlft)k ,uj /z,yiz/*v rn/n t.p/s. The centripetal force provid,vint ryz/,l /n)pt./ zk* fjued 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 50h f ztmw*b0*c:3s tb2m m at a speed of 14 m/s. What must be the minimum coefb zt*t*sc: m0m2wb3hfficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant spij)f +u, a8rj(g1 ejjveed v around a level curve. The coefficient of friction between the tires and the road is 1j8 +gj,r fa)i jveuj(0.40. What 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 negowuh(xz8l:sf3i d ;2 aatiate a 100-m radius turn at 35 m/s without skidding? (Ignored;xh2:3za u w slifa8( friction.)

  A horizontal curve on 5,z/-+ d.bxpno p-jbe 9ztqura bobsled 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 angur sh u+z-16xkle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked hti stc ;c11; ffidb)/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 end9-pza hpb,7jo5nnn1* n fd-fz of a string is revolving uniformly in a horizontal circle of radidz p oann95-17*-j pfzf,bnhnus 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 dmgus 1f/)z(yp ot18b accelerates at a uniform rate to a speed of 45 m/s in 15f8op b)1 /ygmz1(std u 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 q*s5mguc5b p ,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 standing on the Earth, due tp1qax8y5mp5 z ubd4;di: 2ynhmq7 .ck o the Moon? The mass y;pm d ah15 7i2:c4u qkny8.pz bxmq5dof 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.3 ms(wko ao5 nv1 xh40u9qvny; If the masses are moved to half of their initial distance, wv hou1n oxn5q a(vkm9403wsy;hat is the gravitational attractive force?

  For a spacecraft going from the Earth vw7 wc94ed;j; b8wqtstoward the Sun, at what distance from the Earth will th;twbq 4 d798wjw;c vese 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 injoe, iaj +e 7rg9+v,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 outxz69fp0v 0 ba+)jqoff for a "space-walk" at a distance above the Earth equal to the radius of the Earth. b qj)a 6of 90f0fv+xzpWhat is her acceleration due to gravity?

  The radius of the Earth is R. At what distancgr-8x k*ihn4w e above the Earth's surface will the aciw -8rhx4gnk*celeration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equalyfx0j4j/rwl- e,;ygqxf8z, s to 3 times the radius of Mars. Tf0xzfyqwg sr4 j ,y/x-8;j,el he acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some pliq r6w0t8 )dbsanet's center, the acceleration of gravity is rtqw)0b68 sdi $32 \; m/s^2$. 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 t/s 7qy xa4lgqf g*-6dz* sho4fkb)+pg he Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, whys4z -46g qxok/a* g)lpb+sgfq 7 f*dhat is its weight?

  By how many newtons does the weight of a 100-kg person chang64ocxywjnj *8 e when he goes from sea level to an altitude of 5000 m? (Th*jjn cx6yw84 oe 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 point 3r above the Eaz04)o*,oxs -beu2g49h1wz dp w ijqdd)i dpg;rth9u j gidi*b4 od)odgeq, ph0 x1sw4- pdw)z2z;'s surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and z u.3f;.nf rof2 xa+yftwice 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 of this planet?f f zyrf;.x23.o+uafn

  During a lunar eclipse, the Moon, Earth, and Sun all lie oi4gmq92a3 ej2n ck ,lgn the same line, with the Earth between the Moo 3j4icg k2,nq ge2mla9n 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 twn psoyi.l+ )6he 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 thh ,wx yh3k shvhz3,-8er/a9kge Earth (i.e., it just skims the surface of the g3xvhhh er-3kk/w8hy, , zas9Earth). What 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 orbit abqedt+(fgkhvi e. k332lwjq 3)out the Earth (i.e., it just skims the surface of the Earth). How long does it take toe+i3) .3gedl (whj2kqk vq tf3 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 surfajengu*v, (lm+rsky 3.t-i) yvce of the Earth. It is observed to have a period of 89 min. What is the ynjivv trk(m3u .+-)sly ge,*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 diameterf. ; knx3qeho4 j0xhwq d9v*h. 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 with a radius of pt w9jpepd7nwbukhcp s,j0 0 j1s64. 8$422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly circular orbit w sv+h)p(n-jes. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How )-v( wpjhsne +long does it take moon B to complete an orbit?

  The planet Jupiter inbgn 3,6,3qui allk:is $7.78 \times 10^{11} \; m$ 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 avkbko3 c/8*xvrerage distancec 8kx obr*v3k/ from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)