Is it possible for an object moving with a constant speed to accelerate? Expwuk0js e0he93 (z33si s: uqrxlain. zrsxe0:w3jieu 339( h uqsk0s

  Consider a particle moving with constant speed such z gt0 pmb*t rl ch7pg,r8b,l6u; yfq4,that its acceleration of constant magnitude is always perp04q lbbc6gt rz;,f,rl,8p mgh7 *tuypendicular to its velocity.

  An object moves in a circular ,gbp:jl u -cym,ekrbpf :1e1(h 1 g/ewpath at a constant speed. Compare the direction of the object's velocity and acceleratl p,1 f:ecbh- gyu rpbm(k1wej:,ge 1/ion vectors.

  When an object experiences uniform circular motion, the direction of the acomo:;o l 8ng;bdi tu1/celeration i8 ;: dob o1giml/;ontus

  Consider a particle moving with constant speed such that its accewv3;,4 ajzhv f ozd1*wleration of constant mfdavw*3 wz4,1vh ozj;agnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant splc7ty;rv 9)3l s:vz i.kkh2upeed in a circular path :7 pz3ty livu; c9v).r2hsk lkexperience?

  What force is needed h o;q)3wjx5dljvfautkw nk: 4 e.:; 6fto make an object move in a circle?

  When an object experiences uniform circuqdy/60+ltxu.(ztjhew) wp+ b lar motion, the direction of the net force x+ul/d et+qwhp60 .j)ty wb(zis

  A roller coaster car is on a track that forms a circpy 2y q l dl*vz7:2r:r4/nyrra ,gb.xxular 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 this poi,ya:rr4 x2 /2rz* l7vnq x:bp yldr.gynt?

  A roller coaster car (mass = M) i6 d vzml( ajog4-:r*uqs on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the trav:qaj*umld(o 6 g r-4zck 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 unpet/ 0qm r39g)jw br*wtil it is going straight up. Just as the plane is at its lo* /r g3p9)rb0wqtjmewwest 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 radiuc*hm p/gfigvm,(p8cmt *- ko 0s $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a c0ukc 04shuu4jtpn k2x 3wx u,cjs 16*curve of radius r at a constant speed v. Then it goes around the same curve at half of the originaltuu6 kux0,34wc4 0p1*sju ncsk hxj2c speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at d gwpsy5h 8w46+ bnz . 8cpdgsgxs6okna44b8(a constant speed v. Then it goes around a(n 8d4p xgb dw4y6wnphosb.a54gz8+ks 6sg c 8 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 first?

  A car of mass m goes around a banked curve of radius r with speed v. w3yye60r kxzy;nbcu/a1e5 l3 If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal kraec/wu365nzy0bxyy;le 1 3component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobgflp;idr20 d q,vqg*8+t b;t rsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the ru t2fdbrp8glq rqig+v,;d0 t*;n) 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 pcgpyxcd:tq.t:y63w d lm9(; 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 (9gl;wd: x mqycd:p t3ct.py6of the turn. Why do they do this?

  Is it possible for an object moving around a circular pa yf)yf-)8p)hp xxg8dk th to have both centripetal and tangentd-fk)y 8)f) xy8xpg hpial acceleration?

  The gravitational force between two obpe 8f4susuybfs5- xm/il5.:*w z9q r cjects is proportional to

  The gravitational force between two objects is inversely proportio9lk:n yh. kn*ckis3( wnal to

  Two objects attract each other gravitationally. If the n q720:ft,jhurt4n bog0gv+u distance between their centers is cut in half, the gravitat4tg v h7ungqt+ron00bj, fu2:ional force

  Two objects, with mado38ho ix rh:d)9d+kqsses $m_{1}$ 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 u.b cxf09 .yak:7gntzsses $m_{1}$ 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 gravithgl6t9gtx 1)t ation.

  Compared to its mass on the Ewk: kh 49r0tw6znl /ao9opt*sarth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it i p1az76 ql-zhms on Earth. An objea7m1q6zzl-h pct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the roc+c1am 0p325bl hwhqseket's weight

  A spaceship is traveling to the Mob, zd21cc5iiy;2pgx eon. At what point is it beyond the pull of Earth's ci1y5g b ;22xci e,pdzgravity?

  Suppose a satellite were orbitpch- j/ru:9 oting the Earth just above the surface. What is its centripetal acceler/ oc-9 prjht:uation?

  A hypothetical planet has a mass of half that of the Earth and mza2bj)ywce s9//w4n:3 b ovja radius of twice thw9e)vb3 nmzb 2:/oaj /sjw4cy at of the 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 gravit5x7yt np6n h0v9 db)jqy on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Ear9bdtn )h670xvnqj5 pyth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of ve5 +t5r-s ujyhv:y7oplanet A. If planet A has mass m, what is the mass of planetyu5 jv r7o5 +sveyh:-t B?

  Two planets have the same surface gravity, but planet B has twice the mass of pk,gv y x04k9ublane, 0guyb xkkv49t A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheri 1h nx94*zyr,.odxvbhcal planet (mass M). Which expression gives this satellite's orbital ,xr bh .dnx9h* y1zo4vvelocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit.:: v)uot bc5kj Compare the two)ov tc :k5:buj satellite's speeds.

  A person is standing on a scale in ahy2.q t .ynrk:lq4xa3n elevator accelerating downward. Compare the reading on the scale to the pern.3q4r2 yyhat .xql :kson's true weight.

  Who was the first person to realize that the planets move in ellipticaa//m;8zh zz jcv+l i2al paths around tha/ az /j2i+lvz zm8ch;e Sun?

  The speed of Halley'kf6)qh 0.qou 98/y)clhprlj ws Comet, while traveling in its elliptical orbit around the Sho0qlq l/))9r8fuyp wch6.k jun,

  Let the average orbital radius of a planet be R. Let the orbitalhtml: d8ryu 95 period be T. What quantity is constant for all planets orbiting r h98dmly:u t5the Sun?

  A planet is discovered to orbit around a star in the galaxpo on7t50bpzq lm k0912tkg3 ey Andromeda, with the same orbital diameter as the Earth around our Sue1ko0 5 tpm920lzbtn pq37kogn. 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 orbital period?

  The average distance from the Earth hwv98h 1a3lghta 9w0xto the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in on9ag3ha18lvw xw0 hh 9te-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. ryx*6-r2v ed.*uvz;vbal4s x

  List the four fundamental forces in nature*q *nb6x)k tjdo*t g8 wy9ns4j.

  An object moves with a constant speed of 30 m/s on a cirgre i u;+8to8ub 7zlj5-rhd/bzyd ,n1cular track of radius 150 m.;ibr u 7byrl5n,dt8/z1e8hoj-uz dg + What is the acceleration of the object?

  The maximum speed around a level(svg1: tklow flkit-0jkb z z.6,d.(a curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.)o6,kdwkfj1 ll.zz : 0-vt.(kb(t iags

  What is the centripetal accele)qw,-jviifz3 6 y;yiu ration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bi; 6wif yyziiq3v-,)juke is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m hf/ b q27 m0kpbisy,q1from the axis. What is the centripetal accelerami7q/qbf2p,b0k1 s hytion?

  How many revolutions per minute must a circular, rotating space station :mwt) q4spf i31d;wyb*w2 x3bpt f-huof radius 10txiw)wm24bybq p1 s:3 d;fuf*ph wt3-00 m rotate 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 r egl;nga ww5x)3o4ty..e9lo uadius turn at 96.5 km/h. What is the centripetal force on the motorcycle? oleagoe ln 4w3y)gux.;5.tw9

  A 0.50-kg mass is attached to the end of a 1.0-m string. vo9 y7r+, 7cgv*)qulv m6vxq )o3cwrbThe system is whirled in a horizowqv org7 c6lcvo x r+v,))v7ymuq*b39ntal circular path. If the 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 s8eotd08:cnz ztring and whirled in a vertical circle of radius r. At the exact top of the path the tension in the s08d zcoe8:znttring is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is76ce xj,16qfy j(oumi attached to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is e6xfou7qyj6ci1j, m ( 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 accele1sht rf+ / x4nd;aytz7ration of 4g when pulling out of the dive. What is the radihdty/7fa 1ts4z+;rxn us of curvature of the loop in which the plane is flying?

  A pilot makes an outside verhuzgp hb;lj+y(l w9 2,tical loop (in which the center of the loop is beneath hip lh j;h2ywu+blz( ,9gm) 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 fast is he going?

  The maximum force a pilot can stand is about seven times his weig 3+yhd7m m9 u,svr:vk;bs br1eht. What is the minimum radius of curvature that a jet plane's + k r 1yehr:suv7vms9d;m, 3bbpilot, 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 rn)sbc )p/k -vuadius horizontal 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 coeffici/k sv-pb)) uncent of friction between the car's tires and each road surface.)

  A car is negotiating a flaa-uv+0emyb4c0n u r2gt curve of radius 50 m with a speed of 20 m/s. The centripetal force p-4by rg0m2nav0uu e+crovided 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 spe t wny2kbbm/0b6.3q9g iowy(o ed of 14 m/s. What must be the minimum coefficient of friction between the 2 ibby obq9w60nm3kt .o/( gwytires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level cc49g8mwlr qy -k6viq,urve. The coefficient of friction between the tires and the road is 0.4 qrm6w,g4y8lq c9i-vk0. 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 Olymplw3qx7 .d8 ( sov ro2zpu*lqh+p:yw :eic bobsled to negotiate a 100-m radiuss2qqp(zo. :l:wl +*oxrp 78dhy uv3 we turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ruyj+pc-vq4/ d en 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 anglubs8f5 te hk:p.j4 z:te of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at 6b)6c jkbvye7 $45^{\circ}$. 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 strs4itn8 62nqh wfq,r k4fqga/ ,ing is revolving uniformly in a horizontal circle of radius 0.5 hqtwqr8f6,s/24 nfg, 4iaqkn 00
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 r2zl7rloacerq 6. l79sace car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track ofsl.ceolrla276z79r q 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 oq3rodkk)l,c vl4 428u 5fotiuf 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 pe stzf3iec ,9cace( hf.-4l8iorson standing on the Earth, due to the Moon? The mass of th3e 8c .io,(c sifl9f-t4cheaze 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. If the masseb.xfdjhx i:b*)t8 qj-s are moved to half of their initial distance, what is the gravitationax: bh)dib*.j tqj-fx8l attractive force?

  For a spacecraft going *u wf767s awy1ivnu2rfrom the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth vywn 2 us1iru*a77fw6 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 Moone+2/ dmyuom mqzz-9 0v 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 al nxqxj-0 ks *0f /+ack8bqj0v "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceqjj0n08 csvkkq0l/f*x +x- a bleration due to gravity?

  The radius of the Earth is R. At,ey0nnc ) s9cj what distance above the Earth's surface will t)en9 c sj0nc,yhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 time- fvlhkp2 4 wpte.oe;3s the radius of Mars. The acceleration o 24p-eoe3ph;f twkv.lf 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 p )w8yt,3l j4)jr othpmtal+ fhz+d3t.lanet's center, the acceleration of gravity isd3p.htlfj t y+z , ml)jo4h)+ta8rtw3 $32 \; m/s^2$. 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-ha/b su 7k a.-fc7mzejm hr:- Earth. The Earth has radius r. If the object is raisebf-z -7hc-s ha .:j umek/mr7ad to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does thg m)3n0 3qmpnte weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth is g)0q3n pmt3nm$6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is atm)0 / 9;dnb ohvd -f8p,qtkon)tjro4 y52hxnp a point 3r above the Earth's surface. Whan to4)r t)dd,5b8jo9nq;/ 0ynk- p po2vh mfhxt is the satellite's weight?

  A spherically symmetric planet hastsv3,gmjuwmj5g 6 .6nz /(l wz four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on t,w6 zm n6/5l3 .jzvmjwt(ugs ghe surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same l* ggs9d (j3ypeine, with the Earth between the Moon and the Sun. The Moon has a egdsjp9 *(gy3 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 iq blg39 e/pf9nbah+- bs transported 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 *irkm(7 cf89un(uy hszv )b 3gabout the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius o3*z)vunysu c g89m(hf(k 7irbf the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit c ed*4g h9)eu:q3as2 a muov)wabout the Earth (i.e., it just skims the surface of the Eargs342u qd:a*a)m c ehe ou9wv)th). How long 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 above the surface of the Earth. u+bom;,coklyt55 .x oIt is observed to have a period of 89 min. What is the massc. lmx;b yo+u,t k5o5o of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diamete6yu5 h.v 1(oq b+e guj)ip/)r3rrvug or 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 v s183ss vbky: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 orbi io-j t+0q+ eywf9 zvgef,*i ,xsc4s(its. Moon A has orbital radius 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 c (s+iq*,f e9y,esvoz 4wtx-0i +jfgicomplete an orbit?

  The planet Jupiter is u (6k 7f*ukch4xwdx2jt.bdt/$7.78 \times 10^{11} \; m$ 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 10,q/6 phjyeppl 8fxh/ 2 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sun hqepxj/l /pp68fy0h ,is $1.5 \times 10^{11} \; m$.)