Is it possible for an object moving w4s kvtz)+ nv,hith a constant speed to accelerate? Explain. hv ,t)vsk4+nz

  Consider a particle moving with constant speed such that its accele:mftta6e l r+ lm,b+/wration of constant magnitude ltl+/rm tbw+a:fme,6 is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the directio/cz fyz,40wbwn of the object's velocity and acceleration 0f/wy4 ,wzzbcvectors.

  When an object experiences uniform circu lu.vtzl b.j;3lar motion, the direction of the acceleratio.;j lbtl 3.vuzn is

  Consider a particle moving with constant speed suulxtu74cuicb/o++ )5o/ p km hch that its acceleration of constant magnitude is alwa) 5o lpiku h7+u4+txumo//cbcys perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a ct*6s-;vp acw aircular path experiea a6w*t-vps ;cnce?

  What force is needed to make an obje rs5ufhs, :br tt1jn+,ct move in a circle?

  When an object experiences uniform circular motioluk6so ,1m 7iyn, the direction of the net forcim6k ,1 yoslu7e is

  A roller coaster car iscy+8undon.6mv ea+i3 on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of dcnyua o+.vn+8im6 3e the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass =5 cvkb/ zvba:;z p+ t(o26dj5iy9:mgyx7k ihu M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the tto6ja;:7z/ck mgp ikz hd2yv (xb+iybu:95v5 rack at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vy :i kcv: b.ibsbi,t; s;:wu/yertical dive then follows a semi-circular arc until it is going straight ub kwi;s::ybyi.tvb ;s/u ,ic:p. 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 ofis45 en)yv )ic s7rg7i radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curvezds-9 vw2x8 cj(0td nb of radius r at a constant speed v. Then it goes around the same cu nv8dz9b0-d2(wxcjtsrve 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 to the first time?

  A car goes around a curve of radi*uw c 7k jrgg7lsif-z/i5qm7,us 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 tk/g7 ziqrl-* ,7 5jgifc mw7ushe second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r)aac/3u+8 . e0 npcv.sqn/b grkar9an with speed v. If the road is frictionless due to ice, the car can still negotiate the curverka 9au3av.rn/pbs.n/g) c 8cnae+q0 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 bankexji kyt,zp//+s2 3 vbbd at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on yi+/ /ksxz 23vjbb ,tpthe 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 bobsled track isc1e va+ ua;+iq not constant, but increases upwvieu 1+aqca+; ard 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 object movin-cmly.bcy/ av.q , zr0g around a circular path to have both centripetal and yc-vmar.,y. c q/zlb0 tangential acceleration?

  The gravitational force between two objects is propor5-lnmvz w6sg;(:duj wtional to

  The gravitational force between two objects is inversely proportm k4r6// ;tdz ssxafc8ional to

  Two objects attract each other gravitationally. If the distance between thew q 5vp21rxh;lir centers is cut in half, the gravitational forcer21lvw; qph 5x

  Two objects, with mas 2rfp(:/os0em;gx 9ij:lmrs r ses $m_{1}$ 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 masses4wb.(fizays sv 7 w35r $m_{1}$ 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 gravitatioek ck1f i4y(9t8reb2tn.

  Compared to its mass on the Earth, the mass of an0zsltb rn ; ;6mgq(0fv object on the Moon is

  The acceleration of gravv d;bt c hwtp.j2kkd) pd6(n43ity on the Moon is one-sixth what it is on Earth. An object oftck4b3p pd(.2 td;dj6)n hvkw mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fl1.gso-7y(;hnxl*l e mk w va0rom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what )s /0oo oq4aifpoint is it beyond the pull of Earth's gravit0q)4f oas oi/oy?

  Suppose a satellite were orbiting the Earth just above thehfbhk0v 4wuk30o*r a 6 surface. What is its bv4 kh0*3urw0fhka6o centripetal acceleration?

  A hypothetical planet has adu zw 9h4*n/fa mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravityzafdu*49nhw/ on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon iur/9 l44jdhld s one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compar/4j hl 9l4dudred to the Earth's?

  Two planets have the same surfa33+: u 4dztpgk0s w:lofm)uspce gravity, but planet B has twice the radius of planet A. If )t o043 kzm+su:pl up3gwd :sfplanet A has mass m, what is the mass of planet B?

  Two planets have the same su65 r/u*8f8ac(k4x6kwn z o3wj/xx y :f vupjdgrface gravity, but planet B has twice the mass of planet A. If planet A has radius 6d o/x8u3a n ykwr j/fg46(ucpzwxv:5*xfjk 8r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (y+/nio0sq rd8qjd f5wc b. n:y.y f0i(radius r) about a spherical planet (mass M). Which expression gives this satellite's orbit iy nfs+q5yqcd0w 8of .d(b0/rn:.yijal velocity?

  Satellite A has twice the massnglw2;58vud x of satellite B, and rotates in the same orbit. Compare the two satellite's sp d5wgnl;vx8u2eeds.

  A person is standing on a scale in an elevator accelerating downward. Compare t3:k o/d)hntu, made2y he reading on the sy3k/h):da u n,dome 2tcale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical paths arntg)- 5; j(vrlt eirz1ound;eri5jl( )r1- ntgtvz the Sun?

  The speed of Halley's Comet, while traveling in its elliptical oyjvl bs 55n7dj8tam+ vdgl ;bcjj43..rbit around the Sun,jlc5v +sb7jl 8gn jvtdb45m;..jy3a d

  Let the average orbital radius of a planet be R. Let thmee t (4x055hyfj,a,rgg4 cmje orbital period be T. Whe5, cg4(e t0mx5rhgaj m fy,j4at quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, wirikjl u 8m(1c+th the same orbital diameter as the Earth around our Sun. If that+( l1icm ju8rk 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 ith/vni,aod kl1m052the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. Wham,nvto 10h5ki ia 2dl/t is the asteroid's average distance from the Sun?

State Kepler's laws.bd8l26r 7ik 8 6w+ cszrovcu2l

  List the four fundamentofn(fups2i/a2*/m hq qd 60g ral forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of rad1bbb/1a2j,ip ty mxd3 dcse /(ius 150 m. What is the acceleration of thep e1bcjdd/t,bai21b (/3y xm s object?

  The maximum speed around a level curve i ht yn0v1enki- (nq,e/s 30.0 km/h. What is the maximum speed around a curvetnnykh1/vn0,e - (q ei with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the pex k.z+* k,jro d7*trvsrimeter of a bicycle wheel of diameter 70 cm when the bike is movinv7*r.zo+,xrk *s k jtdg 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the ax 2f0r*o rrgyf,;y1sf sis. What i f;so sfr 1y0ryfr,g*2s the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space st (see1/do+aswation of radius 1000 m rotate to produce an artificial gravity oa eos(w/e+d 1sf $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radi)ccv; elm7kkx 1fhf.0 us turn at 96.5 km/h. What is the centripetkf;.m71hcl) k 0xc efval force on the motorcycle?

  A 0.50-kg mass is attached oll-stl* w:zoj; mz8,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 cozl m *jtl l-8;,sozw:an 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 anw6iv7r7wb (qad 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 speed at this point is given by v76 (raqww7bi

  A stone, of mass m, is attached to a strong p p8/01zbx dnqstring and whirled in a vertical circle of radius r. At the exact bottom of the path z 801pxpdq/bnthe 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 600hp9m 4u sy237xc9.d;r mkx jhm m/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of kmmdh.u7xs92cpm 9;jyr 3hx 4curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of tm tb gbg15dasee8*m v8t,to.9he loop is beneath him) of radius 3md .v*9a1ob5sttg ,8bmeg8e t200 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 st6z6j 4sfo.6+sv ybqzf.y jga r (b,si:and is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical d v+i.f.b6y 6a ,jzfo6: 4ybsszrsqgj(ive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with th:0ddd.ncx7q eq 5i v1ne tires on the verge of slipping. How fast can this car e10v:q5d.ddnx ic7 qnround 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 m/s. The cnf-tyhef;p06.;py lk-y4v si1v 1ykmentf1k- 06;sy-lenk.tpiympv y;1hvy4f ripetal force 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. What m,6ttwx*jqo 23:s tlv must be t3xs, : 2t*mj6tto lqwvhe minimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v a orca,kcgp1w80d oa 782mif;oq 2pwq0round a level curve. The coefficient of friction between the tires and the road is 01q822cdkw,7;wimoa oagc 80ppo0r f q.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle i4qu4b :jrrl :bs required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frru bqbj:rl:44iction.)

  A horizontal curve on a 8r)w5q hfjkc:4h it l9bobsled 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, ba 4wt:xafkfhj+++nea); i-l wbnked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is28u6liez t nc9p dk+y5 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 strfksg-in(vb)j ap kvh k; /0+;ning is revolving uniformly in a horizontal circle of radius 0.5; i+-vhs)vj/nk ;kn0 kg(abfp 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 pl pm1yb rg7,m+ zox/dtn(vnrpi); g;.t cif49 it 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 valuei7try4 .c npl;b9dr m+p(z 1)gv/tfo ,ngmx;i 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 prob(mb ;lgm,k t2ton 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 pepf07rd9m gn 3srson standing on the Earth, due to the Moon? The mass dn7rg3p9 0smf 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 force between two massesahvff2rvi q p3)nutq2u0r07 , is F. If the masses are moved to half of theirf vina p ht2 720fqu,qru3v)0r initial distance, what is the gravitational attractive force?

  For a spacecraft going+6rtd,*dbacvduf 5gs 9:s n 9h from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to t +9r5sg *dcn9dvh,:fdu a6t sbhe 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 bmowvx8wy(7 ; 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 above the Earth equal4e flnwhdb6n z.1/7ci to the radius of the Earth. What is her acceleratiofzdwi7c .64 en hl1n/bn due to gravity?

  The radius of the Earth is R. At what distance above the Earth'd5c f,vyy(8 zsfl0tr1 s surface will the acceleration of gravityyyf tdv0( 5fl81 szcr, be $4.9 \; m/s^2$?

  A satellite encircles3 um*jk mydy6h9w76zm Mars at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the sate7 myymh*6m9 36kjwd zullite, 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 8lh//s/41pw bto;qiec7pw9 r riv. w cacceleration of gravity i;rswotcc/w18/ p9lr/hw ip7.iv4qe bs $32 \; m/s^2$. 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 Earpb 5;cpwp:kbsclr rt i7 /9;;ith. The Earth has radius r. If the object is raised to a heigbs p:lp;ckribc5t; ri/w 9;p 7ht of 3r above the Earth's surface, what is its weight?

  By how many newtons does the s9 w68ugu4jmr;8f8g 5ratx wmqp jlb0:2s9t q weight of a 100-kg person change when he goes from sea level to an altitude of 5ufw9xja88u9; l8grpmw6qm gs5 t:2 trj q b40s000 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 a point 3r above th 781tt clhz/) rlji agb.q 27jr((fcmwe Earth's surface. What is the satellite's j zrfrg7iqmcc)t(al(lt1wj 82 h/ .b7weight?

  A spherically symmetric planet has four times the Earth's mass and2hyj8c-a-j5c m x9d d+ d4omnj twice its radius. If a jar of peanut butter weighs 12 N on the surface of thej ajcx8 d9 +dhnm-oj-4c2yd5m Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, s mgwsbd: b qs2+9-y;zEarth, and Sun all lie on the same line, with the Earth between the;s mdz2+b:-qw b9s gys Moon and the Sun. The Moon 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 trauoxn/2, wt9, lhd:gs jnsported 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 sk8w 66 zobqa/j *;lngxlims the surface 6l/a6zb lw*xjgqo8;nof the Earth). What is the 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., it jus1tf 58b3wn1 m (kjg0ip;pd7 fyei8z nfpo+wu*t skims the surface of the Earth). How long does it take to make one revolution around the1jw8;pp0fp5 (nz3knm*w o7+ti f e1iyb8udgf 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 tyry2d9a;o)dlbmg2r5v*(n kp:xx n5 qhe Earth. It is observed to have a period of 89 min.yp nldo )2ra2 gqmbrx 9:yd(nk5 5x;v* 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 an orbit lq.h8z5 1zr *;ybetxgal 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 w krk1 0ijn/5axith 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 orspe+fw 6/dr :fbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to compl6fperw+ s/d: fete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is tbz kf+:l0vr4qhar9 1 $7.78 \times 10^{11} \; m$ 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 orbi h.+ oj:ej,/on n)xw,xb8z hjbt the Sun once. What is the average distance from Jupiter to the Sun? (The distanc,:jw8enjzo nj+ ,x / )bx.hohbe from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)