Is it possible for an object moving with a constant au wi04a.4 ,8hsmth gnspeed to accelerate? Explai huw4,8hismtaan.g40n.

  Consider a particle moving with cons; :kml e82vim/ub2umn tant speed such that its acceleration of constant magnitude is always perpendiculm/nm8ibm :v;u2ku 2 elar to its velocity.

  An object moves in a circular path at a constant spg4ozety 3d+d/.i/ t.hh * metteed. Compare the direction of./th teg temhit.yod43 +dz/* the object's velocity and acceleration vectors.

  When an object experiektbyug 4qy0 6 *2x+rcz 9:bsixnces uniform circular motion, the direction of the acceleratio46 rt*c0+2bgyki z bqs xuy:9xn is

  Consider a particle moving with constant speed such that its accefnfrqy/ 4wozzj,-) g:leration of constant magnitude is always zf4rn/zo- jqgf :,wy)perpendicular to its velocity.

  What type of acceleration does an object moving ww q3ihkjy )j2 aifu,26i f-fab)vm2* fith constant speed in a circular path experience?ba* 22 ha wuq j3jf6fvimk,f))-i2iyf

  What force is needed to make ihw5ev (jltxl6( :a3w an object move in a circle?

  When an object experiences uniform circ1/w+pb5icx q8zakqu 0ular motion, the direction of the net force c qw +1058xqp z/biaukis

  A roller coaster car is on a track that 4yk 7+d9vtzc al ,vf+kforms 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 value for its centripetal acceleration at thkd+ac9tyz +vfk v 47l,is point?

  A roller coaster car :4q ,nzarpe zu/exq 10v2;wkd(mass = M) is on a track that forms a circular loop (radius = ,k;4 u :0ranezw1qqxv2/d zpe 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 minimum value for its speed at that point?

  A pilot executes a vertical dive then q :r *qevl2cxp5,l- kpfollows a semi-circular arc until it is going straight up. Just as the plane is at itp rxq-l*kclvp ,2q5:e s 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 rad9rw/eektd,8 uius $r$ 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 it goe*f g-bym45 +mj 0yz;hcpsd5yfs around the same curve at half of the original speed. What is the centripetal force on the car as it goes around ym*4f;0fmg jyp5dh-yz cs5+b the curve for the second time, compared to the first time?

  A car goes around a curve of7z-wqd+fs56 0tqnxda radius 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 goes around the second cut5 -6 d+za0xfq7nsqdwrve, compared to the first?

  A car of mass m goes around a banked curve of5b p:/ibnbe4e ,do* pu 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 the car from the road is equal in magnitude4e 5bb /: nippdo*ebu, to

  Two horizontal curves on a bobsled run are banked at the same anfewzk.d) b, im pep 40mm 9-cm-,uv*yegle, but one has twice the f,,z mdmm ek0mp-e b)c9wueyi.p *-v 4radius 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 Olympic bobslykw56 aj +u3e. u+oftced track is not constant, but increases upward from the horizontal+af36tu k 5.yjcoeuw+. 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?

  Is it possible for an / )z 45chsow,626 bcgrxuzs76h fo5xzm3ho hwobject moving around a circular path to have both centripetal and tangential accelerati2hc zghbsh)o 46 6co 5zwr/x,hwxz763 mf5uso on?

  The gravitational force between two objects is proportionad7)/pcgs -r xql to

  The gravitational force between two obx3i4r/2dp m; 8xfnvyxl, , zsnjects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between zqfkm x/l o5(zf 74mw 84vhxv7 )6x 8eahhar9ytheir centers is cut in half, ta f v e 8 78wzy)/(49mr5xaq6hk7 4oxhlvxzhfmhe gravitational force

  Two objects, with masses ;civx a3z0 . y-hyw/ql$m_{1}$ 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 mas;l+c84k f4i;xaxcpta ses $m_{1}$ 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 unih6q c*uc24ke tversal gravitation.

  Compared to its mass o o:u64 cq9j g8u+4ldntyd iw-sn the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it/e6hrktq7 4aml3 3btu is on Earth. An object of ma7trab q6eu3ml 4k3t/h ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth' m ;j/oqok)+wvs surface, the rocket's weight

  A spaceship is traveling to the 91f,iu: oo ( dndmw7fsMoon. At what point is it beyond the pull of Earth's gravity?fod7wnf(oi us d19,m:

  Suppose a satellite were orbiting tgq1,dumxz: koz7h*21ga 7sbmhe Earth just above the surface. What is its c ,omm* a21bzx u77q z:k1gdghsentripetal acceleration?

  A hypothetical planet has a mass of half that of jowvpk8g0 tmcc9i;l j q5078po6rv x,the Earth and a radius of twice that of the Earth. What is the acceletlgvvp r8009piow; q 67c xj c,mjk85oration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. The rvs)d 1ub): cg5c* ca/deur y;radius of the Moon is one-fcbuu/g)s ;dcrd5e y:* 1)c rvaourth 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 has twice gj(mom6 k,f3dthe radius of planet jo g3k(m6d,mfA. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planhj: 6ky(1np:1odbgx u et B has twice the mass of planet A. If planet A has radius r, what is the radius :ypujh:gob 1(k6nd 1x of planet B?

  Consider a small satellite moving in a circular orbit (radius r) abo 3niq4d:fwbr0x jd)qhc pd ,(;ut a spherical planet qfxdc ;njpr03i )d (wbh4:dq,(mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the m)5f i+mylcuj:r8eicj 34ux2 rass of satellite B, and rotates in the same orbit. Compare the two satellite'sf3jyj)r8:cr54ie2 cmi+uul x speeds.

  A person is standing on a scale in an elevator accel*)t4 cw,mtn )qfa-cmlerating downward. Compare the reading on the scale to the w,m-mtn)f *ca cl)tq4person's true weight.

  Who was the first person to realize that the planets move in el x9ts3(qcg m/tliptical paths aroun3/gxtcsm9(t qd the Sun?

  The speed of Halley'hf navy * 19m2hwxdjnvpf2*+pw+8 r)ls Comet, while traveling in its elliptical orbit around the Sunf*phw* 2x+9nrwd l1fm8h nv)2+vpyaj ,

  Let the average orbital radius4/0rmqxpn zh0 qqd1g/ o58yam of a planet be R. Let the orbital period be T. What quantity is a z/ 18xymr5h4 0qpdn0gmq /qoconstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromedapgqj2 fon .a3uc v)3)wsu;sh( , with the same orbital diameter as the Earth around our Sun. If 3u; p3uaq.)cgo)n2(svs fwhj 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's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomisonj uuk. a j5:kd8ig9,pq5d( cal unit" (AU). An aste9:uq8k,p kin 5 d g5asod.(ujjroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.13)yte p-ma hw

  List the four fundamental forces inhpad3k8 majh57 dr6hcs-m) 6c nature.

  An object moves with a constant speed of 30 m/s on a circu.*.0vlqf odr flar track of radius 150 m. What is the acceleration of the o*qv.f 0.d florbject?

  The maximum speed around a level curve is 30.0 km/h. What is the maximu:d:wo*(xe, qu vkgl5p m speed arq:op,v :degwx5 klu*(ound a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration o * zn-5maa-xucf a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/snza a --x5um*c?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from +5jf pxj0( u- ( talvjv7as 3eqg*e qbbz63q-fthe axis. What is the centripef3 jbefstbp6qeg +z 3vqqjxl( 07aj5 u-v-(*atal acceleration?

  How many revolutions per minute mjammo3+h+m k/ust a circular, rotating space station of radius 1000 m rotate to produce an artificim+ 3/hkom maj+al gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes aron8jzp;tk i9)b und a 13.7 m radius turn at 96.5 km/h. What8i jp9bn tkz); is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m smo0 h 7t/c(jdxh2ujqqs2 +)frtring. The system is whirled in a horizontal circular path. If thec hq 0f/ouq7rd()2msx +t2 hjj maximum tension that the 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 a strong string and whirled ieb .pe;jo(isti3b5y 7ve (ftux69lx6n a vertical circle of radius r. At the exact top of the path the tension in the stri eex 3jyut7 .xtvpf6 9i6blso e5(b(;ing 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 whwcg(3 twit75dk 7ou)lkxy3 :tirled 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 st:w(7)y okct3tu5lgdit37 xwk one's speed at this point is given by

  A jet plane flying 600 m/s experiences an accelerx8sv3 4fcrt rhqc;)w5,+ zh h/mc2uaqation of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the planf,xq r3hqmh85c2hc;/cs t a )zr+vuw4 e is flying?

  A pilot makes an outside vertical loop (in w21fg r0 ul2d ipg5k2oghich 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 hi22goi02p gdg 1lu fr5ks normal weight. How fast is he going?

  The maximum force a pilot can stand is vrvk +-e)4qbznr .+z gabout seven times his weight. What is the minimum radius of curvature that a jet plane's pilob. +qerr -4+zvvgk)nzt, 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 wit4:k2zny1lyp ut1j 2 ye k6yhp4h the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume6h:ky1yeny 2jky44t 21zlpu p 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 speed of 20 m/s,)yxdsgz qzk:cs+0 q0. The centripetal force provided by fqxg) :0qkzzs,dcy0s + riction 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 of 14 m/s. What 8 mbc1 :,zzdjay*0tdmmust be the minimum coefficient of friction between the tires and the road for th z ,mzyjmab*:8d0 t1cde car to make the turn?

  A car is moving with e,bbsfm 8;jm1v8j qb9 p eo06ca constant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. Wpc8o ,0jqm; 6fb e9esb vb1j8mhat is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking ag4uw mk5/jhy/r k/2 vangle is required for an Olympic bobsled to negotiate a 100-m radius turn 4ah rk u2ky5/g jwv/m/at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve ondix.23qiqntx .)ks+ m a 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, bankedwy 6w oes(d4a: at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked atk dj2f, g1trf224zsid rdxl* / $45^{\circ}$. 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 string0, d7l gmen(5wehi0ze is revolving uniformly in a horizontal circle of r, e w (0deeg7iznh5ml0adius 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 accelerates at a uniform ratsx9qx zj9pv3wq6na7 g /i6 ,qte to a speed of 45 m/s in 15 s, movq6/qs9jgzqpi6vax7 9tx, 3nwing 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 consilzsu6ab(5-vs)jc)i fe, i )b ssts 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 standinb34aapoq pb8. (dw,ik6vy9lg7z0 q kag on the Earth, due to the Moon? The mass of the Moond48y . w(0bq gz3 i76kaaapoklqv9pb, 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,knd(3-be u pu:ox l+p is F. If the masses are moved to half of their initial distance, what iuk eb:,- np3pluoxd+( s the gravitational attractive force?

  For a spacecraft going from the Earth br ij1oi) rq,1toward the Sun, at what distance from the Earth willjr ri,)qio11 b 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 tnxjdx2q,bg pz(,p87fr2 l. b3;tkftis $7.4 \times 10^{22} \; kg$ 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 z aj z3zue 1p1ywp,58cv3k-ljabove the Earth equal to the radius of the Earth. What is her acceleration due to gra z1c13l3z,ekjjpy8 zuwv -p5avity?

  The radius of the Earth i3w4 sm9kwhz8j s R. At what distance above the Earth's surface will the a ws9 43mwjkh8zcceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 timcv7jg08,a +:r xim4h lv ugzy7es the radius of Mars. The accer74yi lgj:,v 7ah80m xzg+ cuvleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km zj pbjc964t5 jucwwiv(8 .di1from some planet's center, the acceleration of gravity4wb89c6twi zp(uc1v ji5jjd . 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 tiy44 uginjqq6160r inhe surface of the Earth. The Earth has radius r. If the object is rai4i0 yijir1 n4ung6qq6sed 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 whe38jl7 wu gl a,a.62emkg)n(kod1 b vnmn he goes from sea level to (e6kgva3lado2w,1bjnm n. 87ml)uk g 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 cgw-qakaiuuvwcg q73 7a,9uz 5 ea+.2kg is at a point 3r above the Earth's surf q 7z7acg+5uaikqvwaag.e-uwu 3 29,cace. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and+4ne( vhc5e1be5ddh f twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it wei hde4cb5enhd(1+ev5 fgh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all liez dfebg ru+; 4/0ru)ba q8dk6e on the same line, with the Earth between the Moon and the Sun. The Moon has a mass ofbdr e086ur/ a+zgq 4 ;eub)kfd $7.36 \times 10^{22} \; kg$; 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 thut;+cpu8d,b1vi.r x xva8u q2e 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 ae,7r4v +mo n -y0stqyzbout 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-vmnt + 4yoe7 ,r0syqz $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth5-mz-(j6 xgc cf jf4 w+xrnvq; (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of thf-(xj+-q jvc6g;n wc xrz4fm5 e Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earta41z i .3(qwyefbucd/h. It is observed to have a period of e1(.d b3f qyua iz/wc489 min. 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 a w 8y* de+fjcdel 08u;q9v4vkqn 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 o1zz axty6 ji,**ltpa;rbits 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 nearly circular orbits. Moon A has orbital radiupkr;5 ay/ e76qgr/ tyz74z.kzavw; uhu-b 0ci s 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 compv.zrp47 75k;b y;/ /yuaq-ew0a z6rzcu ikthg lete an orbit?

  The planet Jupiter iscyq 9-myh4r6hza1cf 4 $7.78 \times 10^{11} \; m$ 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 average 07cr y9d7 jajj.av+spdistance from Jupiter to the Sun? (The distanc 07jdjsc av+.jp9a 7rye from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)