Is it possible for an objkj)b 6z/ jlmv.ect moving with a constant speed to accelerate? Explainlbjk6/zvj . m).

  Consider a particle moving with constant speed such tha 5bfd3g kud9mxfgw aw7 m,;0:yt its acceleration of constant magnitude is always perpendicular to its vel;5x dygg kmf7b:,9wwa 0 mdfu3ocity.

  An object moves in a circular path a h2 3kp(r/nphvt a constant speed. Compare the direction of the object's hpkp/3 r(2hvn velocity and acceleration vectors.

  When an object experiences uniform whvi emtkjn1 6b31 :+fcircular motion, the direction of the acceleratii:f v11 6+jkhntw3mbeon is

  Consider a particle moving with c2owwtut / q.0u*q5 nel2lnf q5onstant speed such that its acceleration of constant magnitude is always perpendicula0t l*e5f qw t qqnun/l252uo.wr to its velocity.

  What type of acceleration does an object moving with constdtko/v q;x45ekm4botot+:l nal 2w 5;ant speed in a circular path experien:qlox4tk5ooktt+bv nl; e5 4 2;/adwmce?

  What force is needed to make an object move in a circle?ptr rcoc. c-m-ygm,06

  When an object experiences uniform circularuxz5,8-kbke9zr p(oi motion, the direction of the net forc 5b-zz 8ike( k,9uxorpe is

  A roller coaster car is on a track that forms a circular loop in thepw*zj6 fb-em 4 vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at th-jfwe*b 6zm4 pis point?

  A roller coaster car (mass = M) is on a track th uuh.q eo8s7 rxmqix n5u+8;.hat forms a circular loop (radius = r) in the vertical plane. If t ohm8h+xq.uqnexr 5i 7;u8u. she 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 thxn /(uoye(z a7en follows a semi-circular arc until it is going straight up. Just as the plane is at its lowestzua7n(ey/xo( 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 curve4b)mub(z s, 4y.ktzcy 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 radius r at a constant speed v. Then icceb6 +h,hn rm/0 hk, fc.mgp6t 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 tof /.nk ,mbe+hc6h p0h cr6,mgc the first time?

  A car goes around a curves. 507s 07h *wo4gyc a -vrrrn*ujfjjc of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What .a7f ygj 0j 4uvor scn c5w*shj-0*rr7is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked cuh 4;ah kd5kk2cyl.sj -rve of 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 theaksjdyk4c -l.h 2h k;5 car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but one ),qlfife;;pd 1ryq8u has twice the radius of the other. The safe speed (no friction needed to stay on the run) fory;efd 8rlf) p ;1iqu,q the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant,6c5n/ nh p(eh du* 1vzqbdv s)-3bao9c 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 tur ah39 bbp-suqco(h1e)/znncd v*56 vdn. Why do they do this?

  Is it possible for an object moving )+xolf/9ku af dk+ w3k7xf78inryl h;around a circular path to have both centripeta + ri d hwk7k9xlan3/;klou f)+xy87ffl and tangential acceleration?

  The gravitational force betweelh* .g 9dnxflki 1u-pp6u5sk0n two objects is proportional to

  The gravitational force betwdk-pkoq *i2,)8wcrhl een two objects is inversely proportional to

  Two objects attract each othe89/*akyuqi9czf j( , drcu t0rr gravitationally. If the distance between their centers is cut in half, the gravitatk *a 08yqc/,fd9 tjz(uc9i rruional force

  Two objects, with masses nxwe12c(x v) s9. 5yflinody)(av2cg $m_{1}$ 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 masv4ws83gmxk plbpc z65rs2()/, 4 xjiv pvc-kyses $m_{1}$ 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 ofd;b t u8 c3wnu 5jiydj/t5o*r. universal gravitation.

  Compared to its mass on the Earth, the mass ofaydfxu z5t y wd/)+i62 an object on the Moon is

  The acceleration of gravlfc-rr4)ck3s - b1eszity on the Moon is one-sixth what it is on Earth. An object ofcsez-s1r bcl4 fk-)r3 mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's su6z.i u6b ux1mfrface, the rocket's weight

  A spaceship is traveling to the Moon. At wb h9c;vkr8,tihat point is it beyond the pull of Earth',r;ih9 8cb ktvs gravity?

  Suppose a satellite were orbiting the Earth j;;fhu xz;vow1c-ag zt-glb 7-ust above the surface. What is its centripetal accgl;ohu7;- xgztabvw1-z;cf- eleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twiczii6 .w8xkvc0 e that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to graviwz.6xck0iv 8i ty at the Earth?

  The acceleration of gravity2jqxdjs* ki44 on the Moon is one-sixth what it is on Earth. The radi4i j kq42*dsjxus of the Moon 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 planet B; .e *a:w gz*-owlv/knxo:i of has twice the radius of planet A. If planet A has mass m, what is the massv:w;g/ *ieaz:fo-. ol xow* nk of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass ovbmtpzk0.,g ( sdg +5fn.kkf.f planet A. If planet A has radius r, (t kk sg.b5fdv .,kz+f0n gp.mwhat is the radius of planet B?

  Consider a small satellite moving i03ng mqb t6nn3ynaz) )n a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellinnymb6)qt)nnz3 ag3 0te's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. C87;kj 8bdlb l81igf r0oq;ns -vt,hkzompare the two satellite's l r7f818hdi zkn;vqg kt,b80;bjos l- speeds.

  A person is standing on a scale ib. i30z4m aig(qygn. un an elevator accelerating downward. Compare the reading on t 34iu.bq0nyi(zmg.ga he scale to the person's true weight.

  Who was the first person to realize that the planets move in ellipenw )8yb/ 4yaxtqn4n 2tical paths around theb teqnx /y)24nan 4wy8 Sun?

  The speed of Halley's Comet, while traveling in its elli36* ux.kkvoen ptical orbit around the Suou x*v3e nkk6.n,

  Let the average orbital radius of a planet be R. Let the orbital ped+t.m9-70kdtaw feub l1pd e;riod be T. What quantity is constant for all ;ddt1 fled m.t+7bw-e 90p kuaplanets orbiting the Sun?

  A planet is discovered to orbit aroycs8 iq 0sp 93.qz5zlnund a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the macsiq3.z50 znpl 8y sq9ss 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 as one "astro5 +2 ddte0**b motzagknomical unit" (AU)tm d*kz 2geta*b05 d+o. 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.pakgzi zke d- e1 .*(nev2x**f

  List the four fundamental forces in nae vlm71 )d:3vu (dssfnture.

  An object moves with a constant speed of 30 m/s on a circular track ok ww4cxjjtlm*18 -v-m f radius 150 m. What is the acceleration ofm8-- wlj4kjvcx*1mwt the object?

  The maximum speed around f uua*c 9q vm4bdc876ya level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radiufad 9c bq*86vucm7y u4s? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter -kf;7qh.orolxq. -w/,6xgmd9g m tf bof a bicycle wheel of diameter 70gh- ;rw/x g9mf m, qo 7txk-bld.6fqo. 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 uhntay8gh++ wp re 8k2.- d/fjm from the axis. What /hgt8+2k p+nfyd uh ew-8jar.is the centripetal acceleration?

  How many revolutions per minute must a circular, r8oxr)ugwm ew ob))65tv-* rlrotating space station of radius 1000 m rotag) r)r wvr-we 6)o*bolx58tmute to produce 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 at 96.5 ns9zl2,jq4vt km/h. j,4 z29svnl qt What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached tx7;.5s nv.cja+ufc n. uddg j9o 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 withstand is 350 N. W +v7d 9;ds..5gfuax jncnjuc .hat is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached9ur-7 v;ay 2jzl prfm: to a strong string and whirled in a vertical circle of9vrr pzf7 ;-2lma:uy j radius 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 s9,-c4a hgmcr ptrong string and whirled in a vertical circle of radius r. At the exact bottom of the path the,4c ghp rca9m- 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 zi + h6 us :mc7,8l1szil1mqib4 *niqtm/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in whic11:sz ,zut 7l* cbm+q8qm i46lisniih h the plane is flying?

  A pilot makes an outside vertiezrxs7v,3v+s1up o6yqqqs p d86r 2+hcal loop (in which the center of the loop is beneath him) of radius 3200 m. At the ssvu y6+q18e36sr dp,z7vx+rq ophq2 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 stai+4;xbbi 3xt pnd is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out ofxb x p+4t3;bii a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s roundmgof,)b2jmk +7k x ds9 ng+9xps an 80-m radius horizontal curve with the tires on the verge of slipping. How fast2g j7xmxgbkf+os9 ,+ nkmdp) 9 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.)

  A car is negotiating a flat curve of radius 50 +w dx.xp*a c 1o 125(svroszypm with a speed of 20 m/s. The centripetal force provs x(* zovyps p cd2w51.xr1oa+ided 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 55ne7p6g o+zq g0 m at a speed of 14 m/s. What must be the minimum coefficient of frictipg6 5+qgez7 noon 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 coefficientra7f8:d5p s wp of friction betwep75p8df :r aswen the tires and the road is 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 negotiaterlc+gvck( 95hy .tcz7 a 100-m radius turn at 35 m/s without l(h+ v c.t7g9cryzck 5skidding? (Ignore friction.)

  A horizontal curve on a ieekl:d 7ab)7 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, ban5 ; oghtbuh 5h+tvd2zaj2f.r4r k 11qfked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is kbbtq2 u0)z3 doq*rcl/wm4qe r,1cc, 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 revolving uniformly in a horizo(cq6v(u.e/yzq ;:yg/5 tcg guz7nwqbntal circle of radiwcvgyb :c t. qe/gq6q/;7gun(zu(y 5zus 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,im z2gjkir( k,f/xvr, :ipk ,a*n2h:j a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circulxran(irz ,vfpjgkk*i / 2m ,2 h,k:ij:ar 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 proton of mh2ei5iv7)v0 n/l bm5z pjs;qmass $1.67 \times 10^{-27} \; kg$ 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-v,8k iuldca- , due to the Moon? The mass of ,kalc d8-i- vuthe 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. spg,zc9k6z /g3hyt -y If the masses are moved to half of their initial distance,y6 g3cgy t, p-khszz/9 what is the gravitational attractive force?

  For a spacecraft going fromaahj3:r4 x /3e v0yglr the Earth toward the Sun, at what distance from the Earth will theex0:rrh3aya vg3l4 /j 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 aer.wp2c :v mpof :62p$7.4 \times 10^{22} \; kg$ 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 aboeml4fiu( i wdq03.o.g ve the Earth equal to the radius of the Earth. What is her ace.o 0g 4q(.i3dimwf luceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surfacm g9peb7af- n7ej:e iq) rdibs6u0-o 4e will the acceleration 4-s beejq 0ine-g97:ida orup7)mfb6of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface 2( iw,;r:x 3pxdnx-pf uyrr- lg /+pqeequal to 3 times the radius of Mars.ln:y x3r-xd u xip ;fqpe2p/,(wgr -r+ The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 4l2: cjfudbqj5k9r/m km from some planet's center, the acceleration of gravity is5/q4ld29j j: kmucbrf $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N ont;2a*aga qz0w the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's suzg*2aw a;qat0 rface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes from je .5gux p+el.p+j5e gx e.u.lsea level to 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 of mass 100 kg is at rlj lj5n1 d8-ia point 3r above the Earth's surface. What is the satellite's8dl1 ir jj-nl5 weight?

  A spherically symmetric planet has fou/jmtfx 2r nrp4 9g8o9,z /rhqer times the Earth's mass and twice its radius. e4 h /8t,rxj9qm2pngofzr r/ 9 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?

  During a lunar eclipseke+-y q9m)fdpc yyx+os2z (d ;, the Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon ydz9qd (+pfmxo;yy s e+k 2-)chas 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 transporte9ytn ct0c3p6 kq1 j8:mcd ag1zd 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 circul6/ snh8o-v ymuar orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth is o -n86usv/yhm$6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just skiemi )n8 ze8;wmf *qdi +z)a-tjxin)7rms the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius nw tm ;ez e)r axdi*-q+7ijfn88mi))zof the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circ;ttsr9 td8b3-: kh i y5pfkx4sular orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earp 5 dtx9kksht4-y brs8;i3f:tth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter opy tsx0+sq2- mf $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the plq2 5wezs b)ei 1+5tat4iv2si oanet 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 2xwdbo:wln yaf )8:k*281cuzh )t pww 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 comd2z)ht:: wok bfp c 88u2w*na)wy 1lxwplete an orbit?

  The planet Jupiter isogi:mz5sd,q(zd;7uq0piehw :( n 7us $7.78 \times 10^{11} \; m$ 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 zrxl( fx (ku*6the Sun once. What is the average distance from Jupiter to the Sun? (Tx6xrl(f z (*kuhe distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)