Is it possible for an object moving with a 6 dj em nk4.af7otv0c-constant speed to accelerate? Explainekc 0tmo.7vnd f a46-j.

  Consider a particle moving with constant speed such that its u -aarc(*nlnd (-p,kuacceleration of constant magnitude is always perpena,-(cd nnl -uk(*au rpdicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the direction o97dm6mfk+ f u ae0,pnvf the object's velocity and accelef m+uemnvk,p96f07ad ration vectors.

  When an object experienzpw: rvg7m -6 :sgnkddp kh315ces uniform circular motion, the direction of the acceleratvz7:1pgrdwk dk 3n6-5h smgp:ion is

  Consider a particle moving with constant speed such that its accele f2i -bf-)cxg qlak563qdr;faration of constant magnitude -b gf qd3lxi56a c ak)2q-;ffris always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed irf92 r.l+7jdbp wky23 khk(q *bf*fp bn a circular path experience?rkk.hp2r+bp*( y f bwflf*j2q79dk3 b

  What force is needed to)ix-. yw)bohkl/ m) zz make an object move in a circle?

  When an object experiences uniform circular motion, the direction of tuu ql.oy0 /p((s+m ludhe net force is/0p+umd uqloys (.(lu

  A roller coaster car is on a trace0gr x 30j -hr7mc:qwak that forms 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 vge:3 m0aq7rch0jr x- walue for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a zpq. a/f5g/xvb m9l2m circular loop (radius = r) in the vertical plane. If the c zm// q2gp xa9bf5mvl.ar 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 31(9wyyyh prquntil it is going straightw3hryy 1p(9qy up. Just 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 radiuvfdi *+v(29w /r.cvmb .urlq as $r$ 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 cg iwt/ylo6 56sl:0me goes around the same curve at half of the original speed. What is the centripetal force on the car as it golc56l :s0iwe gym6to/es around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Th p *fsd osehu2fxe0*a -)ugw.+en it goes around a curve of radius 2r at speed 2v. -sgw+0fa *oees p *fh.d )ux2uWhat 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.sle( v(2ylc 2j If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of thsj( 2e lcvl(2ye normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled hx kme)b q7n8-08o dumrun are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction )mnq ke7-u8 o80mxhbd 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 z0pyr(3 iusskvb9 9c/ h7 n(pcthe Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsledpcz ybh u9v(cpksn3i0 (sr79/ team will intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a cirapr+n4c td ,r(cular path to have both centripetal and tangentirrdt,( +nac4p al acceleration?

  The gravitational force bw-, 7vn7 fmf dn(skanc3gha d (v50k(between two objects is proportional to

  The gravitational force between two obfk 0*nr;+9)etvdk6n o cxnb)xjects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between theiv (l/ 4s 6aqd0ynzoll6r centers is cut in half, the gravitationald(4v l /z0q6lyn6soal force

  Two objects, with makz5;z 2vw ul3fsses $m_{1}$ 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 ma2f,obqm9,zd b)u4yo esses $m_{1}$ 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 universalq4:aova x8v 9b gravitation.

  Compared to its mass on the Earth, the mass -b6 atf.cw 5xb)i7:+tcwrdp xof an object on the Moon is

  The acceleration of gravity onxcno e d6)iz59uuz//d the Moon is one-sixth what it is on Earth. An object of mae5uuo9/ idnx)6z/ dzcss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from thuvj 5kk4./kra e Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is ir4-do1j0 u6h:ibmvx lt beyond the pull of Earth's graviirjl:4m- h1v bx 0do6uty?

  Suppose a satellite were orb.j,q-vyck+h 4v (uimoiting the Earth just above the surface. What is its cen -vhycm ,v. k+(ji4quotripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius ofj;im:wl d *+qn 5n.zbr twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gjz:rbmq+n nw;i l5*.d ravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Ear/3pbsi c2)kic m go:p1th. The radius of the Moon is one-fourth that of the Earth. Whaib p:c m3 )isokg21pc/t is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has gunqhxhn7 ,sn30 * y9stwice the radius of planet A. If planet A has mass m, 9 70hnn hgsx*3 sny,quwhat is the mass of planet B?

  Two planets have the same surface gravity, but planek pead c+(l eepe7xlg/ 6kncs*n1.52 qt B has twice the mass of planet A. If p g./6 xqeeccp2e5ld (nnpes7 la* kk1+lanet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radiuslshbl 3, ;szhdt3y00 s/8dvma r) about a spherical planet (mass M). Which expressiod3dh;zbv m lta03/ lh8ss y,s0n gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates i2jvdpnef-s1c4 ) x*skn the same orbit. Co21pd4s)v xj fkscn*e-mpare the two satellite's speeds.

  A person is standing on a) 4mad+sfuk. r scale in an elevator accelerating downward. Compare the reading on the scale to the person's t udsma+ .fr4k)rue weight.

  Who was the first person to realize that the planets move in elliptical paths at89+m5s tv ulbq *rg1iround the Su5 ts m*lb18rivg +9qutn?

  The speed of Halley's Cifpy-(4/np z9jm+b yc 4 zgzbzx u2:i7omet, while traveling in its elliptical orbit around the b4 u i+f:zyyjnz9-gc 4p xiz bzp27m/(Sun,

  Let the average orbital radius of a planet be R. Ll fpoe4-3-kanrmqw r40/ abj3et the orbital period be T. 3e ap--43bornm4 0k/jl qaw frWhat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andrbd hq 8 mx*w*c5ryjm3-omeda, with the same orbital diametb h8cyxd 53**rm- jwmqer 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 orbital period?

  The average distance from the Earth to the Sun is defined as o3zzoiw4b g d;0yq5 w1ubgx5x*ne "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroiwd 551y4ug0;zbg 3*xbw xqoz id's average distance from the Sun?

State Kepler's laws.hd4 ev wejmm:* jbi w3107i;y i-;svua

  List the four fundamental forces in nauwqwb0l-f8qt (w+nmz/9 gt-9adnt b 7ture.

  An object moves with a constant sp- 5g 3r92urab 8hacirseed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the ohs8 rar -iu29g53c abrbject?

  The maximum speed around a level curve is 30.0 km/h. What is ci;xdm4vdei) w8 1ku0n v.fa:the maximum speed around a curve with twice8vm 0k;nd:c wxa ud.)eii14fv the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the k j*;t .3bi9ddq5trj fr ,c)ccsmh+ g2perimeter of a bicycle wheel or stb +d jj)k*gfc 3t 2;hq9.r,dci5cmf diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is loc +qoe k/o:dy (vp;r-l3gl jxk*ated 0.200 m from the axis. What is the centripetal acceler/l3- l:kx+keyp ;jrvo( qgd *oation?

  How many revolutions per minute must a circular, rotating space statinm w s/3,d 9r(gu36fqvrt /nfyon of radius 1000 m rotate t ng(uw /ty9r/vs6n3f,d mfr3qo 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,h s*m ,vxvt 4bv+sk:(waxkjl5 ,; jox km/h. What is the centripetal force on the motorcy5*;4sk v:vxxtw, bv mo+ahlj(,j k,sxcle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirled i*;pcj,z5ywn1 mvcx. in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the strin*.vc,y m;xcw j51 pzing is not to break?

  A stone, of mass m, is attached to a strong string and w*s:a;*ysv8 g dh irh0phirled in a vertical circle of radius r. At the exact top of the path the tension in vp*ra:iys 0dhs8g *h; 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 strong string andijkgm37;8 cih whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 time7g8cii ;jhm3 ks the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling ou+p)frjy 1gxjsh6 2s*g t of the dive. 1fr 2yhx sgj+*)gs6jpWhat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside verticalyy/ 3-p0iw)6dah :fgjq8m obt loop (in which 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 weidyw 6ta/y:o0ip-hbqgj8) f3mght. How fast is he going?

  The maximum force a pilot can stand is about seven times his w/*7(s/m:viflq0xz dwwbv:vq eight. What is the0 /swvfix/wb :vqq (:mvz*7dl minimum radius of curvature that a jet plane's pilot, 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 t *(- buv0(wf,rtw,erj+ l.i2iky 7yra+zlbll ires on the verge of slipping. How rybrr+(*lia0lk +wz -vltu2,jifbew y7. l,( fast 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 m with a speed of 20 *5gzk c5bi7ex /pi f.tp 4o:oim/s. The centripetal forcz5:fpi 54/.i7 cokpeoxg*t bie 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 of 14 m/s. W6jq8g k2 grat7x(r ++ere,dpa yueq5 bna92*ahat must be the minimum coefficient of friction aqr7ej(y t9+ngepk a+2b 5rdaea, 6qg*u r8x2 between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a leh vr),n/ir+ac vel curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on the rov, a+nri/r) hcad?

  What minimum banking angle is required , dldse(rt- 44wmt/g ffor an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s -4/smd(w4tf dg ertl, without skidding? (Ignore friction.)

  A horizontal curve on a bobsled rkf 6hempe0h/3 hr(f+sun 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 an*s4cm/rp+ 8hlska9 ptgle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m il5z.b4el4r n m k,rl+ds 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 horizontawxbk.8jv -w4q18emyt l circle of-wex 8. yv81w4 qtkmjb 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 :bi)7 s,bq0-k fjwnivthe pit area, a race car accelerates 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 in the blanksw:,knqi b 0v ji)b7fs-)
(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 covea7jli2 juw/a;gduafa2( :22/e yp ot-;nsynsists 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 standing on bj; 9h o;yg )+3hjxizsthe Earth, due to the Moon? The mass of hbo)3;h9 gji s;yz+jx 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 masses is F. If3iqptg7( hk b o5ge8)n the masses are moved to half of thqneg5 t ip7g()38hkb oeir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at wh r;)j9p ew7.om-kko isat distance from the Earth will the gravitational forces due to the Sun and the Earth c o7ewko r9.si-kj; )mpancel?
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 gkr9 la r ii0a9k5qp(7is $7.4 \times 10^{22} \; kg$ 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 above the Earth m5.grni l* ds:equal to the radius o*lr5.nsg im: df the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance15 gt lb(egl,6;tyhjq above the Earth's surface will the acceleration of gravity elg5t;gt1,qj(6hyb l be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times thevo(9efye )fh( radius of Mars. The acfhf)o (e9 (yveceleration of 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 16rehsmdg: 4a planet's center, the acceleration of gravity is e4sgad6:m 1 rh$32 \; m/s^2$. 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 Earth has y 00+cd8k(cvt (xneperadius r. If the object is raised ty0(k0 dec+pcen(8tv x o a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-krbfg; 3wa(6sgg person change when he goes from sea level to an altitude of 5000 m? (The mean radius 6agbr(g3;sf wof the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass q bvfe+c6 m;7 p9u *e39ufrgkg100 kg is at a point 3r above the Earth's c*vreffqk 69p eb7u+ mu3g9; gsurface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its radypvos6totb,j0686*jaq on-4a) j v smius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface o6sv )qato6 ,as 4 bj6jytjo n*-08mpovf this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line kxh74gme:feie6) h 8j, with the Earth between the Moon and the Sun. The Moongf mi :k47h)6ee8ejx h 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 transported to 7257htlx1 slzmsx(nn 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 tfl0t7/ .insmm jf 7w4hf avz35he surface of the Earth). What is h a7fli3m/wmzfvn j0 4tf. 7s5the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., ik hri1fgeg(p jfd0 ; 84oe,yi*t just skims the surface of the Eartd4gff8kpeiej0(y rg,; h*i1 oh). 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.)6wd uprdga0 surface of the Earth. It is observed to haru)d0gp. aw6dve a period of 89 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 Jupiterkxjpo5c8 7tc,, has 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 planet with a ra; pfv1)sh9w4ybwds g:y3omrjj(h8 urn)*1o vdius 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 0l8wxtyj6)+t rg ui 1wa7.ga ccircular orbits. 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 cw) ta71rg+.c08wat il6yg xju omplete an orbit?

  The planet Jupiter isf29idh ;.l0vk6wf e8ccto nv4 $7.78 \times 10^{11} \; m$ 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 Jupiterny6sn3b4 i)x m- fit/e 12 years to orbit the Sun once. What is the average distance from Jupiter to thnf4ix-mtyb 6e3)/ isn e Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)