Is it possible for an object moving with a constant speed to accelerate? Ep d(m9szw l5c)xplaid( zms 9)p5cwln.

  Consider a particle moving with constant speed such that its acce y+0v 9 jab/t6xgaw q4i547bmmsox;releration of constant m49 oit 5wmsj ;0mag +7xbb qvx46re/ayagnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the ds+ q2 d,-;ekatzf o:ipirection of the object's velos+d; :ofz pitq2ke,-acity and acceleration vectors.

  When an object experiences uniform circular motion, them a*x/g kv-a7gfgu2k+ direction of the acceleratio+-ag* 2 / fmgaxkvg7kun is

  Consider a particle moving with cyjwkpy 9:js9iz4z6 b60s cdr6 onstant speed such that its acceleration of constants6zc4w9 y6 0psbzyrj 6 k:j9di magnitude is always perpendicular to its velocity.

  What type of acceleration does an objet6 tade )mp;ip0r49hwct moving with constant speed in a circulaid erph)469;tt0amw p r path experience?

  What force is needed t9ci hh3s16s1skz 3gppo make an object move in a circle?

  When an object experiences uniform circular motion, the direction of the net9ia3j b:l*rx;ov(q-e )mgeyg force gmlgx i*v-q;3ey(j)or:9 bea is

  A roller coaster car is on a track that forms a circular loop in the vertical pl; kfl +uxgpv)6t9 0q.djbxc o2ane. If the car is to just maintain contact w xf+lk6u2qd0ot9 cb;j.x ) vgpith track at the 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 that forms a circular loop ( i5evya)0ls q(radius = r) in the vertical plane. If the car is to just maintain 0q5s vyi)( laecontact 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 until 4pbvo; b/y.xj ,pbs1y it is going straight up. Jvbyx ps 4,b/boyp.1;j ust 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 o(4y ujag(vu q3e:x *imf radius $r$ 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. Th b -qmfj65xw)nen it goes around thwqmj b6n5 -)fxe same curve 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 radius r at a constant speedafz07vi0) at r v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force onv7ra0t)a if 0z 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 -ooyr k) z3+(-v;qfieuki ii- with speed v. If the road is frictionless due to ice, the car can still nezuqfvk3-ory;e- - o k (iiii+)gotiate 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 nberhyn06-/ zrn v gr 1q2b82mat the same angle, but one has twice the radius of the othen1 vyrgb6n q rn2 /r2-eb8mhz0r. 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 on the Olympic bobsled track is not constai3nsm7 hd2m90x w.5wz:plcx .bph b3rgxe 1i3nt, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn. Wh3x2 w9i5mhgxxweb.zcl:3 i pn d3.srbp70 m 1hy do they do this?

  Is it possible for an object moving around a circular path to have both cen+ a;8xmej8 dd3cf iq5rtripetal and tangential accelc3dqfdae 588 r;+jxmi eration?

  The gravitational force between two objects is prst9p ok5v -u/noportional to

  The gravitational force between two objects is inverseeq s:-faa;hk ukp4 l.7ly proportional to

  Two objects attract each other gravitationally. If lzo,a/kak7 io a (a);+urzg t(the distance between their centers is, koagzr;7a to ail()u+kaz /( cut in half, the gravitational force

  Two objects, with mas70urd1 gfcboxfan;:y4 ) f tr0ses $m_{1}$ 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 maim87hi oc i6-usses $m_{1}$ 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 ldw4(2tao*vj gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moon isb1e3eozbzep6* yd /g3

  The acceleration of gravi7 ko ,n-mhhp*mot*w 5dty on the Moon is one-sixth what it is on Earth. An object of tmp*h,*nh5m7-kd o womass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the 5+ 7go,bd gvw0;vo xyarocket's weight

  A spaceship is traveling to ti cr.9 gbxhzlt* 2m1bxz6x-u vc y56o3he Moon. At what point is it beyond the pull of Earth'sb6 5lxg-2y1c3b96 cz*hxum txiv.roz gravity?

  Suppose a satellite were orbiting the Earth just jpk cqd 4lvhxgk67dng/sp:-+h3. s 1e above the surface. What is its cen/7hslsknd+-1 kqpepjgg 4c 6d:v .3 hxtripetal acceleration?

  A hypothetical planet has a mass ox xodsiw,k qt-o4 4(e0f half that of the Earth and a radius of twice that of the Earth. 4(- oxtid esw4 xqk0,oWhat is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. Tndi;a5jg+i-p5 1im zuhe radius of the Mooza p-j +iii;mnud55 g1n 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 has twice the radius off qpp5 m)n a,5hmkun2/ planet A. If planet A haspmafq,k)/mu n phn552 mass m, what is the mass of planet B?

  Two planets have the saqxgy34f hq5/wah9u-5 6p koxj e /e,rume surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the rk,oure/ uq-y4wepq3 x 5/ gjhxfha596adius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) abiyp q3i:z9cd 6out a spherical planet (mass M). Which expression givez9 cpi :q3y6dis this satellite's orbital velocity?

  Satellite A has twice the mass of satellio;r 29q2fj kxbte B, and rotates in the same orbit. Compare;k xqfrb22 o9j the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compa+bxwrjgj5 0z 6bwx, s4re the reading on the scale to the person's trxj5xw,j6r +zbgsbw 40ue weight.

  Who was the first per ww*)hd)2ojlg() qxsl son to realize that the planets move in elliptical paths around t*o wl2 j(d)ls)q)hwxg he Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around the l vdf n4px8+*wSun,*4+ fdpv8wn lx

  Let the average orbital radius of a planet be R. Let the orbital period bz+(mxg bkj6af5z3s a4 e T. What quantity is constant for all planets orbiting t5j6 (4g3z z+x bkasmfahe Sun?

  A planet is discovered to orbit arouni)y ph e:po5z7:bewmw 23 o;bx +uzr1jd a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If thathzpozypm3o1u b :)j;+eiwx57 2: reb w 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 Eav0ubd3 ofp(f tkz0 x0;rth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's avero;z3tp fxbk0 fu(0 vd0age distance from the Sun?

State Kepler's laws..1b 1, qu24, 8bpwr pvcon:a 3nrkqbnm

  List the four fundamental forcp4 s2xs8y yi,f i/p-e (a3gtyj6g+yloes in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radius 15f:86c4lx4+3ppkffbdp5l : xqf / u iyo0 m. What is the acceleration of the objecf ox 3fi4bdfu4cp+/p::8 q56xllp k fyt?

  The maximum speed around a level curve ij3k:e- ;pgy3e gixnv9s 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors re e k-i y933;vexngjp:gmain unchanged.)

  What is the centripetal acceleration of a point on the perimeter oj,(, zwxi xyf5t)i 8jkf a bicycle wheel of diametyix5)jj(tz,i ,wx fk8er 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at ux- jqbd;b( 40zmygp-o )k0cps*j+ qx 5.00 rev/s is located 0.200 m from the axis. What is the centripetal*x m0)4+dyq-jpbxku0s(zq - pjco; gb acceleration?

  How many revolutions per kl856drm xp/ uminute must a circular, rotating space station of radius 1000 m rotate to pror85md 6 lk/pxuduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radiu40ptve kex z xpp/3 r67,hxkw0s turn at 96.5 km/h. What is th zpk370xp6 /exkhvtwpxr0e4,e centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system isypn *)r1vt ta9 whirled in a horizontal circular path. If the manttya1 v*) 9prximum 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, is0lo8m 3ubqutbnh 95 i;titb23 attached to a strong string and whirled in a vertical circle of radius r. At the exact top otli qmbh5nt 3uitb2;u o0b398 f the path the tension in 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 to8nm qy83 *ou--qhni g90lnamg a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the staq ngyg08q-m 9-nh o3li8num*ring 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 acceleratzpf5x4 zy4.3 sb uk5,0yysf gyion of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyi su . fgz,sz3y505 yf4bxypky4ng?

  A pilot makes an outside vertical loop (in which the center of the loop is be5eyf) mz+fx d5neath him) of radius 3200 m. At the top of his loop he is py55 z m+xfe)fdushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can n,o r.(zf d/(zid es0n f3j3 j/eotf+qstand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a verticaljd(e/fznt, f .zrs03 qe n+o3ifj(/do dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve wof mun)q 4x wvn/+hh7,o.yg)g /ey uw.ith the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume f ngm./ey,4.) h7yg/q+uxun oh)ovwwthe same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 5d 1w02t1 3 la)sii mg2eekeek90 m with a speed of 20 m/s. The centripetal force provided by fre1lki2d9e3 w 20m1seg ka i)etiction 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 ofiswy/; vbhx 8,i9m8bf 14 m/s. What must be the minimum coefficient of friction between the tires and the wb8ybmivh9i ;,8s fx /road for the car to make the turn?

  A car is moving with a constant speed v aroubyd6l589 xqownd a level 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 staxylo896 b5q dwy on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate au )n0zefj/ xs5 100-m radius turn at 35 m/s without skidding? (Igno/u5 fxnzsje)0 re friction.)

  A horizontal curve on a ef0j(dq)m;7ec 9wp)+ ax2gye+wife pbobsled 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 ic s/smm)6;gwil j2 tk. hva2*radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 tvtn y j73l*9em is 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 inws lgc5 )rtr74lj: 9e7pzqt j2 a horizontal circle ofq)jwjt2gcp l se z7rl9t457r: 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 the pit area, a race car accelerates at a uniform rate apcfn tv/uw37yw1l3 9b.bg4o to a speed of 45 m/s in 15 s, moving/fubb 7cg4p3oa1y v3.9ntw wl on a circular track of 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)r3ko tenp+7z 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 kggy cguao. w0 :,-t+pforce on a 70-kg person standing on the Earth, due to the Moon? The mass of the Mo-0y k+g:.cgopt w, gauon 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 v iaufin ,8,a 34vt7nlhri:t5 the masses are moved to half of theirl4 f n5vatt8:n i ah,ir3vi7u, initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from rvm d;nsqhu1)m;m;.c1fj5z tthe Earth will the gravitational forces due to the Sv.dcfzqsm 5h;j tu1;1nrm) ;mun 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 Moon7gq wkqlrowsc 7e :8:h17 jo.l 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 disic 9ew 0z0(buhtance above the Earth equal to the radius of the Ea9w0hzb cei0( urth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above (:9ulx6 noe frthe Earth's surface will the acceleration of g (:or lenxf96uravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times thggd0, kq y3vn*e radius of Mars. T0qk 3 yd*gng,vhe 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 :yya2by wwr,j/y2 :xxfrom some planet's center, the acceleration of gravity is /yywj,ry b2w:a yx2:x $32 \; m/s^2$. 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. k/vjwwv90(pj2bm 2uuit (h( iThe Earth has radius r. If the object is raised/j(hi0mbutvp k2 vj(w i w(u92 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 y;,,fuav h1y(kf5xgcra9g-r t,8 pc h izl8;dfrom sea level to an altitude of 5000 m? (The merh,yhyp-d, (rxfavkat9,; cfg8u5 l zcg ;1i8an radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r.h r;mq s()ii ;avya9i) A satellite of mass 100 kg is at a point 3r above the Earth's surface. v a;hr)y9(is imi); aqWhat is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice ,yiaif z(/kcbuj(aaz0 /ry,t9xi 0 . n8a 8gssits radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much /zt9 iarf .is0cb(8i/ ,0yzna ag(sy8a,ukjxwould it weigh on the surface of this planet?

  During a lunar eclipsejwaa f/7jtg ky*;a/c; , the Moon, Earth, and Sun all lie on the same line, with the Earth betweenya;aa;jwtc7/ / j*f gk 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 tran5pe2m e*zi9 wvmf:3ovx*dlg (sported 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 t*t ed3pt qxr56,b3seo he Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite?q6p3e,t5e *ds rt box3 (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low sa0hf5aii7v*bxj ,d0 circular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius vij a7 ,bx0i*0sa5dh fof the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surfac7duq1ddg i ecz0kf+i93.b- qqe of the Earth. It is observed to have a period of 89 7dq dbq0g z31- dq iu.+9ikfecmin. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupibosd(m7e:dopsb. - o )4tpy+,m8 j rixter, 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:ua a*;-ut5 edy ;yzbcn-o- wz 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 wxe6vpx*x frm6m 5++r,g3)jx-teguu circular 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 com- 6u)mj rx5x g6gture,xmx3f++pw*ve plete an orbit?

  The planet Jupiter isaxeei+-p 8unl1 r 17fx $7.78 \times 10^{11} \; m$ 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 Sun3py lnwutibnecm p qsbv,+8j6y0;5 9; once. What is the average distance from Jupit8j m tn,yl; 63 vncpbw9i q0;bpeus+5yer to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)