Is it possible for an object moving 1hegxzpngl n02 * f4v+with a constant speed to accelerate? Explain.g*vgeh f24zlnp+0x1 n

  Consider a particle moving with constant speed such that emccjl:/qnc1lm 7 y: (its acceleration of constant magnitude is always perpendicular to its yml c/ :e( 1q:jmccn7lvelocity.

  An object moves in a circular pa 9n67ddyhqp 0wth at a constant speed. Compare the direction of the09 6nd7p dhwqy object's velocity and acceleration vectors.

  When an object experiences uniform circuld 4m+nb+s2 vlqar motion, the direction of the acceleration isn+ds4vl2m bq+

  Consider a particle moving with coe ;3gh7y35-spgf ots)7ul dx jnstant speed such that its acceleration of conesf7)lpgt3yu x75dh; - o gsj3stant magnitude is always perpendicular to its velocity.

  What type of acceleration does an object movgk1el.j0bm fb*c50s ring with constant speed in a circular path expefc1be lb*k0.gm r05sjrience?

  What force is needed to makdgn.gp,.oo brb+(br)8un di 4 e an object move in a circle?

  When an object experiences und5pi +xd5 w gkq2 :wle6i0y4afiform circular motion, the direction of the net for5w52d+xialk0dyig4: f q6pewce is

  A roller coaster car is on a track that forms a circular loop in the pv c( hw) m.nuc-d2bn-suaw: .vertical plane. If the car is to just maintain contact with track at tcndw b:.s. nu ch-2)-v(uaw mphe top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that50 fcuawu+f3m forms a circular loop (radius = cf5w +fmu u0a3r) 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 6 9g*hop: 8u9kox*( wahyxaxzthen follows a semi-circular arc until it is going sya9 kux8x*hgow(z o* 9a6:xp htraight 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 r7a*:,tunv7df) s w sspadius $r$ 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 (h c/jizfv a6;speed v. Then it goes around the same curve at half (/iz afc;vjh6of 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 curveka ,mg:z ;wj.i of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. :z.,wmj ;kiag 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,mi 3 ylia(eb8 speed v. If the road(be iml3 8a,iy 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 bobs +cz g;l.gt7iux1ib0 mpz;v s4led 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 run) for the smaller radius curve is v. What is the safe speed on the larger radi1pg ii;gxs4 v;zb mlu0c zt7+.us curve?

  The banking angle in a turn l,l uan .ou)x c6(9nqlon the Olympic bobsled track is not constant, but increases upward from the horizontal. Cl n.onqu 9l)cla(u6x,oming 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 moving 6lcs+:c7 wnubns8kul1a + szk*l5 +syaround a circular path to have both centripetal and tangenc+s+sllw*u157knyb6:ssku z+8 acnl tial acceleration?

  The gravitational force between two objects is proportz+*r7km+ 9 pou2 dvho5y ni.dwional to

  The gravitational force between two objects is inversely proportional tom gng-:) pv6c(yqwx6 u

  Two objects attract each other gravitationally. If the distaf07zd j 1mpff5b6p m/k8k9ojmnce between their cent1zm ff08jm7k 5m p6fjb/d9ok pers is cut in half, the gravitational force

  Two objects, with masses xi;o kt/xf-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 maqu40fhxecd7 f73wrnl0j ok 1e) p+3;* ysdhtbsses $m_{1}$ 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 gravitcp7cg hfzl g r)54mc3.ation.

  Compared to its mass on the Earth, the mass of an object on thjqz8rp3 5z gwis85j+ ke Moon is

  The acceleration of gravity o i,vgotwydb27;-e0 pa n the Moon is one-sixth what it is on Earth. An object ofb, 2wpvga dei-7; yot0 mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from jyxo*n0 +lkd0the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At wh acd.b7zr :dq+at point is it beyond the pull of Earth's gravity?d7zc brd:+ qa.

  Suppose a satellite were orbiting the Earth just above the surface. What is 5nu;13 l.y 4; dqa3dr tnvdbgeitsgd 54;ddtan qy r13.3eun ;lvb centripetal acceleration?

  A hypothetical planet has a mass of half thav82:peqsr n/lt of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planetlervnsqp2 : 8/ in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it ixs(m5kw n,q x(g (i)xhs on Earth. The radn,(xs5 q mg)(whx(ix kius 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 surface gravity, but planet B ha.b3ehrm+ixafh*n m e3 4je)y (s twice the radius of planet A. If planet A h 3 43a.*(x)+er jehyehfnmmibas mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has ys1tjjim,-r n;- 7zoqtwice the mass of planet A. If planet A has radius r, what is the rad rz y-jo-tq1ms7nj;i, ius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) abo6kl4d jie5wi ++.zt zzut a spherical planet (mass M). Which expression gives this satellite's orbital velocitk6l e.+zi 4jtwdzz+5i y?

  Satellite A has twice/t)o fst k6qi+( vbjhfd,q.-l7 )gwbh the mass of satellite B, and rotates in the same orbit. Compare the two satellite's speedsbfgtq7/hwfb))v (o tsid6h,kl+-q j..

  A person is standing on a sca v6q8ez+(zlp roo6q/qle in an elevator accelerating downward. Compare the reading oneq686 l+ov(q qr zo/pz the scale to the person's true weight.

  Who was the first person to realize that the planets move i, bibb:9+9z z0pal kig nbu/j6n elliptical paths around the Sun? zb :ubbi0kibz9a6l +n,/ pjg9

  The speed of Halley's Comet, k/cwmfpahq 5u/-f,t1bykcsv 6e 4 7dyr* 7,jl while traveling in its elliptical orbit around the Su4s5hvmt6ly ,wca qf7k/17pyfb/du, jr*-ec kn,

  Let the average orbital radius of a planet be R. Let the orbital period be T. bf6qovdf q9siqu( : o0*nb 3p9Woqdb9 fp3 qu:q6nbi(f 0s*vo 9hat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with t9 inlg9b -w;fe s1pvaj8xj76ahe same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the pelvf -9xgjaawbesi 98n6j p17; riod of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun i w2yxs* ;obz.erbu l*-kskw,3s defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the3;,b*okey.r uwxl 2-ssbz k*w Sun?

State Kepler's laws.) jjhu r vrqwghi-1k98+) pgs;

  List the four fundamental forces in rup6n q/33hy4(bxxnb 2f ut 5lnature.

  An object moves with a con(kwr m5 o:zmm8x47hm(hxl el.-rr- kdstant speed of 30 m/s on a circular track of radius 150 m. d em xlw:5m( k-hr8o( 7lmm-zk4hrx.r What is the acceleration of the object?

  The maximum speed around a level curve is yzgnf v1-owm l)qt26-30.0 km/h. What is the maximum speed around a curve withvnz-61w2qm t gf)y-l o twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a poin 5h0lj3z0gsve t on the perimeter of a bicycle wheel of diameter 70 cm when the bike i h3es00lgv zj5s moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located m8 r r0/xyx9hovpou u ;()+cv3 zwjdv;0.200 m from the axis. Whao8 9jmchxy;(prvuo) 0rwv /; u +3xzvdt is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating . sjue:d(1tn+2hxa1c3csozo space station of radius 1000 m rotat+j2ntesd1sooz3x:a.1 ch uc( e to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.- g6/aq/qvhl: /;y8dd:m/zxvqt esz r7 m radius turn at 96.5 km/h. What is the centripeqm qg:l:s6 ;/rq v/ h8/ zez-vadxty/dtal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m stri z2x7gmj : pv/l,/ried it6xtt6 u37neng. The system is whirled in a hor:vj / xl7gmtnzprx3d e ei 6/t76tiu2,izontal 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 stringasp zxr;q:1q5f:ig2w 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. qwsi p21x fq:rg;a :z5 The stone's speed at this point is given by

  A stone, of mass m, is attachma ,n58cz/mopi,uu.3u 9 :l g uopla3yed to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path l lncyg,m.3 ,9z8iop uau/ao5m3up :uthe 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 600 m/s experiences an acceleration o.tj 6pxpdiyb f t9ahf2g7,.b)f 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plapx, bp2if7tdh. .b6)faytj g 9ne is flying?

  A pilot makes an outside vertical loop (in which*r/ 7s7zajwyht+1 hzy 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 weight. How fast is he goyrzazs 17/hh7y+*j wting?

  The maximum force a pilot can stand is about seven times his weight. What dro.r0(o o gh+oylt qlrt.**g6 3jkp3 is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolrg*qto+ 3 yrtld.o (jg *po0r6o3.lhkerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 8l+ 3b,xh u)vq3wb+iqi 0-m radius 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 coefficient of friction between the car's tires and each r+ v+q,ii3bw )ub3lqxh oad surface.)

  A car is negotiating a flat curve o mx4)4io7xcmj4:tif p+7ug lxf radius 50 m with a speed of 20 m/s. The centri4m jg74 xpfm) 7tlcxi xo4+ui:petal 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 rad)bf zief -7-wzius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction betb -7ffiwz z)e-ween the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level cj u5 2o,gzmgv4urve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the , go45mvg2jzucar is to stay on the road?

  What minimum banking angle is requ(v jaiwqr3v :4.fl8r kired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frjqlvr ki4rw:av 38(.fiction.)

  A horizontal curve on a bobsled run is sb j5nd w:,klxh 0;x4hbanked 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 atq f bzic4*xmo1l9uk 90 an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ban k2s)vj2,.stu*hbv3l:kkvku ked 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 lw*jrrt 6-fxj -yt d;84ooix a0dy/ +ja string is revolving uniformly in a horizontal circle of radius 0 ;io*/-xla - do6txrtyr0dj4 y+fjjw8.500
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 ac8u p5czfn;2 ; (wvlthgcelerates 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 vlhcp(;;2 5 u8twngz fthe 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 co+qw j r0u0:vgynsists 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 force5c4d mll2 3hjzjyrq.5 on a 70-kg person standing on the Earth, due to the Moon? The mass.qy2zh dl5cj4lj5m3 r 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 masses isk0mre*k/mis aj wt1j )37q( swkmz7q, F. If the masses are moved to half of their initial distance, what is the gravitational attractive force?0qm m*/ 7wtiawqsj (7rk j1km3ks,)ez

  For a spacecraft going from the Earth toward the Sun, l95x):g - sxcxi9vzuk/(gx1izke 7.9wq rmok at what distance from the Earth will the gravitational forces due to the Sun and the Earthsu :)/ 9qil9ez mciwg9 xxx7zx1r. o5kv(-gkk 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 Moon0o/9) xqjnuz ,0a 8fz:vxod*rg. s ldu 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 disxn1iyvr iw4k ng3.(nk+z g0) rtance above the Earth equal to 0r .+(vi31xg)i4gznynw k nr kthe radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above *o+v6dvgis( a the Earth's surface will the acceleration of gravity bi*s vavd6+o(g e $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equalvm1)/ 76oozu ow5yb 5*vemp ng to 3 times the radius of Mm/up vwnb5 5m yo76ego1v* )ozars. The acceleration 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 planet's center, the acceleration of gst+ +mmvjo t 31x(dsld41yl-x ravity isodsv smy3xd(t1m 1l4 +jl-+xt $32 \; m/s^2$. 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 radiq ty)r25g5aw ,pp ib6sus r. If the op ip)awqs 6y52t,5gr bbject is raised 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 when he goes frmi2 ah:i obo ;3ld,9m4z pf6pyom sea levyf4;io dp: aiom96h2 zm l,b3pel to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r.p/b5 s;v(ck in A satellite of mass 100 kg is at a point 3r above the Earth's surface. What is the satelli 5cbsk; vn/ip(te's weight?

  A spherically symmethi(k/a.glda -ric planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface o-a(d/ .h akgilf this planet?

  During a lunar eclipse, then 9g;sre)6fa,o xe0mfcuo*j : Moon, Earth, and Sun all lie on the same line, with the0rjx;,mc* :o)feo6f uesn g a9 Earth between the 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 transporvwb o7o sli354+uot 9gted 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 j*alv)bsto3)2 r/ejrlow circular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satelli*j sv2)e/ tlrja) o3brte? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about tzl*u1i )qt.za m0w+ml,gye 9 bqe/p q)he Earth (i.e., it just skims the sur+ ta0* 9gmi),lqlbewm1 q )yzqpe/zu.face of the Earth). 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 thefo7/5 lz mzw5e surface of the Earth. It is observed to have a period of 89 min. What is lf5e zmz/ o7w5the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupi o9c :+pk9 thzwc20sqdter, 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 orbzrzf8 gflx;/ 7its 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 circulab8ykvb 4.z5umr orbits. Moon A has orbital radius r, and moon B hzuy v54km 8bb.as 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 is-q 8rc q/0garu $7.78 \times 10^{11} \; m$ 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 aven ,o;ts1 x6/y3 ytagws ztby16rage distance from Jupitttz6 ;awy,116o yt3 ysxsb/nger to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)