Is it possible for an object moving with a constant speerr ;f;)f sm9mzd to accelerate? Explainm;)rfz ;fm9rs .

  Consider a particle movingx)x.og- baq:fa -f)cs with constant speed such that its acceleration of constant magnitude is always perpen-sqa-f)g f ox): xac.bdicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the direction l bm .j.6rg9p1oucfywt rr+4;of the object's velocity and acu41gy.+or;6cr jfp.t wm9bl rceleration vectors.

  When an object experiences uniform circular motion, ppk, g7iex h 2w-bg,,*r0c vloy;hp7kthe direction of the acceleration rvki2 g*;gpxoe7l,,k-7 wb0 p, yhhpcis

  Consider a particle moving with constacm (5x 4cryy2adeg1f *nt speed such that its acceleration of constant magnitude is always perpendicular to its veloci 1ymfedr a2(yccx*5 g4ty.

  What type of acceleration does an object moving with 0 vu9uo v6rmb8constant speed in a circular u6vmv r98 ub0opath experience?

  What force is needed to make an objec yrtk )8jpac-0t move in a circle?

  When an object experiences ufow76nx9*/iy/ fh 55wyrt seeniform circular motion, the direction of the net for*fif5e/h ox6t9 s yw/yn5w 7rece is

  A roller coaster car is on a track that forms a circular loop :c3k uw8b3c aiin the vertical plane. If the car is to just maintain contact with track at the top a c3c8:iu 3wbkof the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is onnbg/4 fma /au6 a track that forms a circular loop (radius = r) in the vertical plane. Inb 4afmaug6/ /f 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-circular arc until it nlemh3k 5u1 d/is going straight up. Jemnh/ k51dlu 3ust as the plane is at its lowest 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 rav wx24opu 5sp m+ru(u4dius $r$ 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 ,kfc 8dbv5bm hwqy 8w4 pj1u38speed 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 cu8j8w3yk8b hw5qmp cf1 bv,4du rve for the second time, compared to the first time?

  A car goes around a curve of radaebwy5+/+refco gay) tu2+ h)ius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it ga+o)e/w+cu t y y25bgf+)earhoes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If the +dka ky3( /uvxroad is frictionless due to ice, the car can still negotiate the curve if the horizonta +ud3/vkx(y kal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curvesmyj1nv2j + c .4 yrxs6y6tyaa) 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.1 6yc) vjrsyjat+4xny 2m6y a 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 l0 g31htt c.knOlympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the g lh1tc3tk0.n wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to have both centripeej*znz4t7j2;hx5 q huwx b2 ztd)o +v0tal and tangential vwo7qz;xhtzd*n ju25 240etz+jhbx ) acceleration?

  The gravitational force between two o9y/c*rq*we w ebjects is proportional to

  The gravitational force bet75p ::,hmaq1,onx kcnsjnps+h xq)q7)w ki9f ween two objects is inversely proportional to

  Two objects attract ealu *dyi-2rsif )d3hx (f3wk s.ch other gravitationally. If the distance between their centers is cut in halfxfd* ) fdw(-si32si3.ylrkh u, the gravitational force

  Two objects, with masi7 5g r/ub0;shk1zzocses $m_{1}$ 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 masses am :vcghv;8x6$m_{1}$ 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 un+bz. /kfgqmiuk rm*0* iversal gravitation.

  Compared to its massenttw p;/3s5p2 o 7k:-ax( xz wi;lnsv on the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Es76e7sk hph- ozq ra49arth. An object of massrp- z7ss 4 6qko7haeh9
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, t6fb fi d/f ).-l2dvgm8xdz r00uy; jwehe rocket's weight

  A spaceship is traveling to the Moon. At w9x. v+1 e .cebto ki0a((gvldy:5ahqzhat point is it beyond the pull of Earth'ska+0o e vx. qi1ad g.y5:bh9zct(lev ( gravity?

  Suppose a satellite were orbiting the Earth just above98zv fr bu1d*q the surface. What is its centripfv8u1b9zqdr * etal acceleration?

  A hypothetical planet has a massm0m0s* / rn3:;pby9iym0wibq id: gw y of half that of the 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 to gravity at the Ewp0d qw:/3:nm 90my *gsmrib b0ii;yyarth?

  The acceleration of gravity on the Moon is one-sixth wh2e2 izo5-ewsb*h/ udwat it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the -wio2h/deusbz *e 25wEarth's?

  Two planets have the same surface gravity, but planet B has twice tch,tyjo0iiu2(o4a;9:+k j xx inop.fhe radius of pljh+iii0.,a2 xn o:(kx ;ou4j ypcto9 fanet A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of l; 3* kqni;rb xhj(qwnpq9-lr rqd81,planet A. If planet A has radius r, what is the radius of planet B*q;nbpqh3j r 9( 1ixrdqw -8rln;k,ql?

  Consider a small satellite moving in a circular orbit (radius r) about a sphx7*bl h,,htyaerical planet (mass M). Whia,x,yt hl7hb* ch expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satel9v3h,x wce2ozlite B, and rotates in the same orbit. Compare the cz evhw,o9x32 two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. +7m+uqt)rkh(gjz7od.tug /1sh.x mj Compare the reading on the scale to the person's trueu)djm tstoxrggh. .ku+qm1(h 7j7 z+ / weight.

  Who was the first person to realize that the planets move in elliptical paths ar o+vyve amlz7xu a6n6mw 73l0 ;x*fs3roux l7vz+no3 e3x6rlmf 6 asu7y* wv0a;mnd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit ar1.zqz 3on6 pdw p 6xf-b* f zjt/244er6tqnsghound the 2n4jpo/6zwg-n . r3t 4z1* sd pzxt6bh6 eqqffSun,

  Let the average orbital radius of a planet be Rj kb,4c d7t103kzbs q*yq2 iez;5sof b. Let the orbital period be T. What qu4 s,j 3 b z 17qye2q;0dkzt5bk*fbscoiantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witevcw:*pe9 b+d h the same orbital diameter as the Earth around our Sun. If th ev:*pwd9 c+beat 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 .(e3x4t( 8b0mpxk,5itj1 df ;hfszckm;ly q q as one "astronomical unit" (AU). An asteroid or8 k bfj3lp5kct;mestiz;4qhm( f.,xdy xq1(0 bits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.y2i.lfgk .0kf4whg 8c

  List the four fundamental forces d akd wbu.3 ea-oghx03wa-o0; in nature.

  An object moves with/hm 8gryvr-;ha.*nf t 9((s os p.uypt a constant speed of 30 m/s on a circular track of radius 150 f p(ptya.tns-yh89* /s(ror;h.vmugm. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is t 5 *aj+lf:vro3snmy9mhe maximum speed a*f s+r395m :mjv yloanround a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleqfvs2s1 v /f0eration of a point on the perimeter of a bicycle wheel of diameter 70 cm when t/0v s2ffv1e qshe bike is moving 8.0 m/s?

  A point on a wheel rot ackp7l65fx p(ating at 5.00 rev/s is located 0.200 m from the axis. What is the cent6f75pc a(xpk lripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of radiojm 2dn(.a2 twus 2 atmw.d nj(2o1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a massy;dm 8yp,xgy / of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. y,/dgpxy8;m y What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to rqu6lr1inx3 z6x-d8 *(foidhthe end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string uih(6 8*rxz3riq6- dln dx1ofcan 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 a strong s 2.s4udqhq/ qrs)cpq- tring and whirled in a vertical circle of radius r. At the exact top of the path the tension in the stqp 4q.) sqd-2 /rquchsring 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 7n36zwl;j6 zeb3wt(( ih1adz vnp(ni 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 the1hw z3; awz(nzn b7e6j(6 t(nid 3pliv stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s eq7dmz.g wm7dj6joa7- xperiences an acceleration of 4g when pulling out of the dive. What is the radius ofa77o d -djg.wmjm76 zq curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in whichvdzkg )p 4l 2po3s/jddmh)8)l the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fas)okj )8v l2zdd d3p)4phsl/g mt is he going?

  The maximum force a pilot can stand is aboiu;v/ du8o-3 6rpo6m/l jndnsut seven times his weight. What is the minimum radius of curvature that a jet plane's pilot,jmud8vd/;no-3sr 66 on ul/pi 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)z5dz gn(,8g pot3gf2/x vnacha x5/d the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of fricti(,d/cgn3 8 hdg g5fvz5x/paa2xot n)zon between the car's tires and each road surface.)

  A car is negotiating a flatln9be. q0th z y9 0;/ohbxh-tk)jq3b t curve of radius 50 m with a speed of 20 m/s. The centripetal forct-n0/30; bx zth )bho9ykhe9lbt .jq qe 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 speed o.* umrzvbrz / .)rpc.,aspk ;k0r gema7-(xkpf 14 m/s. What must be the miniczv*. r brpampkmkg(es .a.xkpr 7z ,u0;)-/rmum coefficient 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 coefficientqjee:c 7(yksn3g0fa * of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the ykqse:0gf(nc3j a e7 *car is to stay on the road?

  What minimum banking angl dl2 m+/mda d5y1qkd8( xuous o46k0zqe is required for an Olympic bobsled to negotiate a 100-5u m60oysuqkl4 dd81 aqx+/z 2k od(mdm radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at a3:vwzkg-n9 g x $45^{\circ}$ 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, le*;x:qnf +i fvbvys+x xk) +.banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankef tb1s;3 92 gqkzjnedx/r33vpd 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 revolvingqm k +sd)z4lh6 uniformly in a horizontal circllk)6sh+ 4d mqze 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 car accele sa3s1 8rg7,bgf5jqxx 6mwt8 trates 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 i8 ag3qrsbf jw6x1t8mgxt 5,s7 n 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 proice0l+2gxk; g ;-jvqz8nfxgoz.7;kqton 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-kgc4 c3 ;mwequnr4n n2b)*u /spg person standing on the Earth, due to the Moon2cb/nm4w3u ;qn ge *4rncps)u ? The 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 qr9f4 dee7cs t2zwyh1)cmd4;tz :8aq masses is F. If the masses are moved to half of their initial distance, what is the gravitational attractive fo8:z2 wq9h drdqe;a 7c4tytc)1ez4sfm rce?

  For a spacecraft going from the Earth toward the Sun, at;z3p;let3m e t what distance from the Earth will the gravitational forces due to the Sun and the Eartht 3 pe3el;;tzm 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 uhj3y *yvk7 p)mmju-)abw9 h;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 ouz,oh3z8t ov5 wf eew8;t for a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her accelevo3 5w ehzz o;,wt8f8eration due to gravity?

  The radius of the Earth is R. At what distance above theo x;y4llqikghq2zl1r6iw( dy91 )je; Earth's surface will the acceleration of gravity be;2qjh1xel zyr)l6; 1 9kqiwyod(4igl $4.9 \; m/s^2$?

  A satellite encircles Mars at a 1ycq9nl7dv g5 distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as5lc91q7 gnd vy compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some plx,*;lgyob) ra anet's center, the acceleration of gravity*g o arlby,x;) 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 surface of they+ yv ma61r5ua Earth. The Earth has radius r. If a5 ayry1+u m6vthe 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 a 100-kg person change when he goee 2p qq6oz bi0x7o4d3r6ar ag2s from sea level to an altitude of 5000 m? (The mean r032o6igo q ad74pzqra 6rx2beadius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. o0kq5,u n.s9x zp+tsz A satellite of mass 100 kg is at a point 3r above the Earth9+ zpx5soszq ,0uk .nt's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's m/pq 8ysdcn,a(.qf -ll ass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much wo.san(p qcq dl f,/-8lyuld it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the6meyll-)*ksji*be 0tx ol21w same line, with the Earth between the Moon and the Sun. The Moon has a mass o* let*bm k 1i0o6)wes2ljxl-yf $7.36 \times 10^{22} \; kg$; 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 txb3 knsbpahds u/a4bki n r*4*r 4u,.;he 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 Ej9+s k71y+bzgp;o jagarth (i.e., it just skims the surface of the Earth). What is the speed ; yj19+b7jsog a+gzkp of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular+:i qr6p mpdg; orbit about the Earth (i.e., it just skims the surface of the Earth). How 6 p;id mqg:+prlong 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 abo zg:l5jo/ttqu/qwth;upp w(m, *q ox 3f2d8v9ve the surface of the Earth. It is observed to have a period of 89 min. What is2: 9/(tq /ju85x;w gwvmzdl3o*fpuo,qpth t q the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has kqt3d5syv aqw p3j0(u0zmxwyh 2;21s 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 planz ap;ci5f6/1 iz w.c * +-u quj8mbsk(ljnade7et 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 orbital radius r/f9+rr*bh5n sieey +fd.sr,ke d/k2m, and moon Bm.kd i2f+ kr9 s/fr+ r*e,/ed sehnby5 has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isc-. l xv7q xg0 z:nbd+s1eib5d $7.78 \times 10^{11} \; m$ 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.vvqla*2 hb1m6 What is the average distance fr 6hvvl *b2m1aqom Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)