Is it possible for an object moving with a co uq.aa64n0 n/ymrh f:instant speed to accelerate? Explain.m0h/y: a nu.afq4nri6

  Consider a particle moving with constant speed such that its acceleration of con,2qip2v0u n bhstant magnitude is always perpendicular to ivhpub ,q0i 22nts velocity.

  An object moves in a circular path at a constant speed. Czk8+nbjl d*lve+r m, ho) cr6+ompare the direction of the object's velocity and acc+vrdh+ 6n+zl jk8 ecrml,)*boeleration vectors.

  When an object experiences uniform circular motion, the direction *spgc1a0vj zc 39w1a: a rxx ,(f(vy.b2r yagdof the acceler(s(xgcryy0p1 ,cf . raza:3gvxab* d 9vja12wation is

  Consider a particle moving with constant speed such t6e2k-1f)il52ipq:r.j qrfff3vzzpo , l ph/z hat its acceleration of constant magnitude is alwayspqi,1-5 )l z rfvz2ofeh.2q: p6ifp jr/lf3zk perpendicular to its velocity.

  What type of accelerati- ic kr:gl22m-q.c kpbon does an object moving with constant speed in a circularkcc 22l:- -rp b.gkmqi path experience?

  What force is needed to make an object moves;(wea krp(+ m in a circle?

  When an object experiences uniform cir7p)r 3 (gbiacicular motion, the direction of the net forc( 73bacrgp)iie is

  A roller coaster car is on a tra6tg 64qrgg n 0lxpzy;7ck that forms a circular loop in the vertical plane. If the car is to just maintain contact with x6qp6grnzg7l0y;4g ttrack at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass j+aux/83 t80hqthmds= M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact withdt+hm 3xsuja 8/th q80 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 follos(9*d/li -db-g fzn pxws a semi-circular arc until it is going straight up. Just as i bzld/ndxf(p -9sg*- 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 raezzwy)rz s /;6dius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radiu:*d s5bo (yculs r 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 itold5cys*( :bu goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r aw+z*j tl z2zw6 9kt11nlsulu+t a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force 2j9l+ z wl6w1 t1zszltu+n ku*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 rfy -t ium56l /acr i)4kve+po3adius r with speed v. If the roa vtpcri of63m +e5uy/ )ika-l4d 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 magnitude to

  Two horizontal curves on a bobsled run are banked at thfkogqlgcd3/d g 06n5rs;n: 8ue same angle, but one has twice the radius of thc8 nf/ g3kqds6ou l:n;r0 5dgge 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 o 5/g,)ir qzcxwc(hkmtg)7 i(y 7tq3gnn the Olympic bobsled track is not constant, but in q)ix7n/ cg)(mhg 5iyzq3rg,ckt7 wt(creases 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?

  Is it possible for an oxmpgy:*1 f0ccbject moving around a circular path to have both centripetal andypc1:g*f0m cx tangential acceleration?

  The gravitational force between two obc q1kp r/mrc-:fw;jy:ii4of,/lq g+pjects is proportional to

  The gravitational force between two objects is il lqenjeo7s/3 )h.a1wnversely proportional to

  Two objects attract each un;(t sc)n uilpz+:0mother gravitationally. If the distance between their centers iuu0n+z mc ;pns:( tl)is cut in half, the gravitational force

  Two objects, with masses8jm s8*eogz0y29v mf: vz;nq f $m_{1}$ 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 masmx8/1xkhw9c h;0hc:7jno ppn 4 z2pas 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 universal gravitation.d:jr 2w 3tn-.ql(lp3n k b/jvw

  Compared to its mass on the Earth, the maxyl1 ,7i9ucltn2 sh, vfknl;37wjnf,ss of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth.s-qq3ll87x mr An objec7sm3 8 -rllqxqt of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves awayn qrh3*;6 82 rowyz;yns y*yei from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. g 2:1lfedunvihm9.v/k1f2u wAt what point is it beyond the pull of Earth's gravityf:9vfn.1mv w hl/du2 u2g ei1k?

  Suppose a satellite were orbiting the Earth just above the surface. Wp( h7rojw-;m6.xzdg5 wu(ss a hat is its centripetas 5o7d( wz-h maxuspg(6wr .j;l acceleration?

  A hypothetical planet has a mass 0b(yc 23zlv1obq kudd14wydg; t 8sd,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 od ygd0;wdd3vy4b1ls1,tu bq(k8 cz2at the Earth?

  The acceleration of gravity on the Moon isu pywsn)rr8 ul6cnt;4lo/: rjf;cj,4 one-sixth what it is on Earth. The rut6noj pr ;wsf 4c,y;l: u/cj4nr)rl8adius 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 su( 3dyqyy7tc/mxp:c z2 n2 rm0psx a6/xrface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the masscms z(mx2tayp602c:nx/x7p/r 3y qyd of planet B?

  Two planets have the same surface gravity, but*hfny a o3,.xe planet B has twice the mass of planet A. If planet A has radius r, wha,3fyhn .a* oxet is the radius of planet B?

  Consider a small satellite moving in a cirti, 6ek,4+nwub,15lcofx pic9mrv1icular orbit (radius r) about a spherical fuo9m11t ,li xc c r,nv5+wkb6p4i,ei planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same otml. m; c+t2u1 6bdackrbit. Compare the two sk+ a6;mtmltdu2b. cc 1atellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compare tjdv * z0 4)xopa7ygzn/he reading on the scale to the person's true weighz gjo07y)azx4 *dpvn/ t.

  Who was the first person to realize that the planets move ivi8 bx/zbhb6f3zf+)u nzjwx:(e k f: 3n elliptical paths arounziw f+ 6bx3jv:k3b8zn fxb hf ezu/)(:d the Sun?

  The speed of Halley's Comet, while traveling in i (mpxrk5z*rurk+ecf ++. k3 nots elliptical orbit around the Su 5+z+(om xpr3rr.fnuc kk k+e*n,

  Let the average orbital radius of a planet be ybxb , - avw(i2wk7kv/+gilj0 R. Let the orbital period be T. What quantity is constant for all planeli-x(a0 vwy k7 wb2bigk/,jv+ts orbiting the Sun?

  A planet is discovered tos5wv d6tc bzut (ap b1w.m97,v 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 period of revolution of that new planet be, compared to the Earth's tmb6t(wuz7c dsvbp.,a5 wv 19 orbital period?

  The average distance from th4vyp an:s4g bffl5ld-+u 2q r7e Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asqgr+bf d4l52vf: psu y74-a lnteroid's average distance from the Sun?

State Kepler's laws.;6 uv9d.mha9ck*9yww c g9izk

  List the four fundamental forces in nature6ygkrgs,;+ ch)sf; ym.

  An object moves with a constant speed of 30 m/s on a :ueapy2io f ig.9a1u2circular track of radius 150 m. What is the acceleration of the gi:y2.2aa 9 ioeuup1f object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum sp1 qlrc* kozd.sug*wrf) ,t+xa7bidn.eju865 eed around a curve with twice the radius? (Assume all other factors remain unt.q,k z*oalx+srf)dw8 r6db e5.igu j 1u *7cnchanged.)

  What is the centripetal acceleratf /7x4 pl-0nb+sk.fbr(rcrj a ion of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movi ff-pan(k+r7rb 0 j.lc 4/srxbng 8.0 m/s?

  A point on a wheel rotating at 5.00 2 83bo)h pgi8*mn;ma*nypuxl rev/s is located 0.200 m from the axis. What isx*a8hb) i*pm 3y2l;unmp8ngo the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of r3:prhx+x9 x -t/zbif 5 pdi,unadius 1000 m rotate to prod-d 3zt ,x 9xur /i+:hinxpbfp5uce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1zysz -e4 fm1xb3f6 oe33.7 m radius turn at 96.5 km/h. What is the centrip e y3o1z6b3f mxzsef-4etal force on the motorcycle?

  A 0.50-kg mass is attache(+r0u umuor/g4l.a5xa+y ekgd to 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. What is the maximum speed of the muk( oxe ly 0a5+grm.+/ra4guuass if the string is not to break?

  A stone, of mass m, is attached to a strony5rq a phji)0o9nztq;,;wzqh9lcs* *hq.r5ug string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stone's spe q *9ush)wc;lqq ;a9. j*5 qnr5zo,irypzthh0ed at this point is given by

  A stone, of mass m, is attached to a strong strilwx lxb6 h/vl 5p/z5v3 l;yd9yng and whirled 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. Th5xvyx 36llhwbv5 /z;l/p9 dlye stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an accelerag6 yk90mwdohsk8/x y4 tion of 4g when pulling out of the dive.0ymhykw/6x4sg 9k 8o d What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical lool1b81. zx( qxrg )xazoxxh 9*kp (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing dow kz1xog (lxq x)x.z8x*ba19rh n 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 dvv/sjb0k.+ /)j4 3umsrms)l*yqa kx seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can toled*mv3 rj)sl k bjxyau0/.ms/sq k )4v+rate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horvccz 9h5 d3;ikgs*:ia izontal curve with the tires on the verge of slipping. How fast can this car round a seconahdic;5kz g3c vis :*9d 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 m with a speed of 20 j0sygm )ow a qx):x.d3m/s. The centripetal force provided b gwqm)o:3 d0jyxx. s)ay friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flatuu s:01p xevd *53tbym curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make thvm pu*stex 0135byd:ue turn?

  A car is moving with a constant speed v around a level cp rh2o+*jfu y)urve. The coefficient of friction between the tirufhp+)j* yro 2es 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 requiredcg)(k 7bretx o : /99th6kswyg for an Olympic bobsled to negotiate a 100-m radius turn atb x6k s c/7:ogr9kwhgt(9)ey t 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is ban c9xgy-4 6*ugivu-3pt+/cb mhhwqm3 a ked 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 of a n9u; 7rk/9hi hzu9: iyn;lvk$45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is (sz:*rp fev-(h p5kq7ejl y1 *u7 jh;opqe5kabanked 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 n ,fp)mm8v0bp cx5o4fof a string is revolving uniformly in a horizontal circle of radius8p0x cmf)vn5 f ,bpo4m 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 ratehbg.gu-fu ,1f(* bb2*lbgn bi to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value1buhb i*glb* gbn.-b,f( fg2u 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 proton3w92je bu lgpc(5zdb2 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*e5v d(f( 2rptw+jujm a 70-kg person standing on the Earth, due to the Moon? The mass f +d2mw*5vrpejut(j( 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 fotn r+3 f(o) kcoc,mr6jrce between two masses is F. If the masses are moved to half)3jn rocmrf,(t6 k+oc of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from tx(*ias +x :fnche Earth will the gravitational forces due to the Sun and the Ear *sia: fnc(x+xth 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 Moon8zbdaz/ru- +xg n9yr( 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 out for a "space-walk" at a distance pn.s*o yo;bjd f6u6mpo0 ,pu)above the Earth equal to the radius of the Earth. What is her acceleration d0o;o,bm jp*n.syfppu6 dou )6 ue to gravity?

  The radius of the Earth is46kn5o xtkuzu6 , 7xjo R. At what distance above the Earth's surface will the acceleration of gra 5 67o4tkkujn6,x uzoxvity be $4.9 \; m/s^2$?

  A satellite encircles Mars f7tz7.9-ngop+uzqtq6 )kew gat a distance above its surface equal to 3 times the radius of Mars. The acceleration of wpq z)zt6- n9og7. gf+tque7k 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 planet's center, the accel6 k: :;yuyqz8v pxjyya7kx 3l/eration of gravity is xyzk /p :y;3uvka8lxyq6 :yj7$32 \; m/s^2$. 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. The Eahrsqw 9./v 2z0yev61gfq/pbc rth has radius r. If the object is raised to a1fb./gqyw0q cv6zvr9ph s/ 2e height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 1+xz nw)utza-8 rs11vf 00-kg person change when he goes from sea level to an altitude of 5000 m8z+nxs 11zut- fr) avw? (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 point 3r abovp e1e9y*dgp1ce the Earth's surface*e c11ged9pyp. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its9l* 4;wlp 3lv vrzkh5l radius h*9lkp l5z4;l vlr3vw. 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 eclipse, the Moj9gq k4t x:b4bon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon gb4x ktj q9b4: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 tra otcb py;ctg;n /8g+6 7z)zgvonsported 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 circular orbit about the Earth (i.e., it just skims tw ur.0 ohltj s0b(.gh,he surface of the Earth). What is the speed of the satellite? (The mean radius w. ,h0.rjt0 olg(u sbhof the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.eh5 +ct ed;kl3z., it just skims the surface of the Earth). How long does it tak k5cde;hl+t3 ze 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 above the surface zhi- a(m(fc8g of the Earth. It is observed to have a period of 89 min. What is the maz(g- hc if8a(mss of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an.,hf7yemx -no)4w(dyw iotb 7 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 orbitypu mw-s 10u)*vk0m lhs 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 radiug*wpzyrw w 1k4 +4:v7ksn ,gahs r, and moon B haw ,wyk+4 ga 1pkwvzh4:s*7r ngs 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 ig(,fx 0takf:b 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 Jupiter 12 years to orbit the Sun once. What is the average7hod* pi5 2qo ryr/8la)) ouvl,cpy; g distance from Jupiter to the Sun? (The distance f7 ih r5*oc;r)ap ouy2v/y)8ql ,dolpgrom the Earth to the Sun is $1.5 \times 10^{11} \; m$.)