95.02: An object shown in tqh.vz,f8d2dyai fz * 4he accompanying figure moves in uniform circular motion. Which arrowda.hivz8*,fd f 2 y4zq best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wh.v evstm9ow8 t3b5fn) eel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best 8f9 teo wvb. tmvs5)3nrepresents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a cir3ad0n.( pnyj s+kwc5 n c1 (vzke1h.xdcular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to pdk. +h0 yn 1 s n(51vp(wancez3xdkc.joint Q. Point Q is exactly half-way around the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves in a circular path at constant sptd , 1qzt:y2tg 2.plvm.6p1cj *hu cazeed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q. 6: 2 htapvg 1t*q. 1 zpjmlcydc.uz2,t Point Q is exactly half-way around the circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constant speej)r 2e eq ;qsyq7)fcq7p(ogy arxq266d around the vertical circle shown. Which arrow best indicates the direction ofa( 6yrqpqr7)sqycjo 2qf ) xqg; e26e7 the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small m;xez :/o-sdz qwd r8myt0bf.s+v 66baass connected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mfo q0m.+xw6tsb-ev/zyr; db8 zs6a:dass’s path viewed from above the twirling mass. If the girl needs the mass to pass through the point labeled P in the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves with constant speed aro go/q+z,pdbw:k i3xms2 wae :n8i3s c55zkbl4und a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the l 3/53 8go:cks :zni mab+idq,ew5bk4xpz2ws direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendgc g z-dvo--..vtg. wfulum that is released from the g-wv d.gv. --tgfzc .ohorizontal position at rest. At the moment shown in the diagram with $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) point-like object cy1gjd9kjc,m, )j1zarests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 seconds. The coefficient of kinetic friction between the object and turntable is 0.5,yj)11 ,cjzkcjm9d ag0, while the coefficient of static friction is 0.80. What is the magnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0: -/fyoaap a.l kg puck moving in a circle of radiu a ayl.o/a-pf:s 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on.e6 ar:djqm* n the end of an 80-cm string rotating at a constant j e.qnd m:6*rarate of 4 times a second?

  09.24: A point mass morjb .ov,2 xayb )f8pm7ves along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mafbp2o ,y 7rmjx8b.v )ass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horizokx +d,4,,e g9dn3f7.hnyaxr0t9 i xg sfb9 ratntal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each xyi 0nx 3,9db9e+s,a.t9 x,ffg7 rdk4 grntahrevolution is:

  99.22: A child whirls a inhlmvb (( :,ho1zkk4ball at the end of a rope, in a uniform circular motion. Which of the following statements is NOT tru mhl(kbvz:1h kn( 4i,oe?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a string ay k7cfyb/: m4tnd whirls it around in uniform circular motion. The radius of the circle is r, the speed of the mass is v, and the tension in the strin:ykcfm4 t b/7yg is F. If the mass, radius, and speed were all to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pullvh6(dypjqb5(h:ixy ssh 524a3 q0x bded outward until the string of length L to which it is attached makes a 90- degree angle with the vertical. The mass is released from rest and swings through a circular ar4d(2:6idb hh apyhy 0q3(xxq s5s5 jbvc. What is the tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, sennset k3t( xe jy x+6)agu-*+oe figure to the right. Assume the ct at +*k y3e-) xoungx(enj+s6ar has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. Avotd1:di 7 v*xl3ses 2t the very top of the hill, the shape of the road can be approximated as a circle with radius 25 m, as indicated in the figure. Which one of the following choices best represents the magnitude of the upward force exerte3x: *2ldit e vd17vssod by the road on the car?

  97.13: A small sphere is moving in a vertf4,;gwe j*3rdpq6p -c)tf c byical circle at constant speed. The magniew3b t*;yc)cg,-rpf q4fj6 dptude of the net force on the sphere

  11.47: A simple pendulum of le)o wg:m/62lwn/rb jfvngth Lhasa point mass M released from rest from the horizontal position shown. In the absence of air resistance and friction, the mass swings through the arc of a circle. Let T represent the magnitude of the force from the string on the mass (tension), G represent the magnitude of the gravitab6lrg/ f)wv n/wm2o:j tional force acting on the mass by the earth, and F represent the magnitude of the net force acting on the mass. Which one of the following choices describes the relationship among these forces when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a str ab*d2k2pogu b:)ni-qing forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ) u*qnb gid2okab2:- pranks the magnitude of the tension in the string (T), the gravitational force on the mass (W), and the net force acting on the mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is ahmw)j)q8 9 zoypplied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what hapo)hjy wq)9z8 mpens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionlessc)r-r/lg/h.m 7kk2s4q 9yfcrgxk x8g surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds it at this location by applying a 10 N force. The spring is brought back to equilibrium and the mass connected to it is now doubled to 2M. If the spring is extkqg.r 2/r4khgmsf/9) x x-y r7kc8lgc ended back 30 cm from equilibrium, what is the necessary force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kd gio3v qn18(.;laj/z +us evh+4kea fg mass with a constant speed of 3.24 m/s in a vertically-oriented circle+ olzn ua3(dgek8 jivfsav h+.1;/4qe of radius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labek ie.hw. +v;ifto t.k(va ;tm*led X andY) are at reston a horizontal disk rot ; t+ft*. wiva ..vhkekmit(;oating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the coins from the center of disk is related by $d_x=\frac{1}{2}d_x$. Which one of the following choices correctly identifies the relationship between $f_x$and $f_y$ , the frictional force on coin X and on coin Y, respectively?

  15.40: A 2.0 kg mass is connected to the end orki u4pk3pc25; (w acccuwq.4 7mkrpj:tvg)/f string and moves about the string’s fixed end in a conical motion with a consta.p uw5):rruimjpc( k 4c34vpw7acqc2gk k ;/tnt speed of 4.0 m/s. The string has a length of 2.50 m and forms an angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass iv,:9,dcov oqixf cwu9: 9jne3s in uniform circular motion as shown in the figure. The strincin v3cvoo9:wjxe,9,q:f u9 dg to which the mass is attached has a length of L = 3.00 m and forms an angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g is at rest 30.0 cm from a h * -hw-egrjn a uih(.qhjbopnn2d*zet*h93+5 orizontal disk’s center. The disk starts to rotate frh*j +ehj *nnez9wu-oinh-d.a (r3 bg5h*ptq2om rest about its center with a constant angular acceleration of $4.50 rad/s^{2}$ . What is the magnitude of the net force acting on the object after a time of t=1/3 s if the object remains at rest with respect to the disk?

  10.35 A point object with mashm- xa cdy,.t u*t8a0k 4:cv9ali0bvss M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in t0a-4h,t:d xyv .t bukac9i* s ma0vlc8he figure. The disk starts rotating from rest with constant angular acceleration $α =5.00 rad/s^{2}$ about an axis perpendicular to the plane of the page through the disk’s center. After how much time (in seconds) is the tangential component of the point object’s acceleration equal in magnitude to the centripetal component of the point object’s acceleration?

  16.39: An object moves in a circle, starting at the top, with initiq w6gq(t(v k+ial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclqvkt6 gqi+(w( ockwise through an angle of$55^{\circ}$. The average acceleration for this motion is $9.8 m/s^{2}$directed straight downward.
What is the final speed of the object?

  16.40: An object moves in a circle, starti*qnbd)fs5tp p s ht 59jm0e(y9*svv2 qng at the top, with initial speed 17.0 m/sv y5h5)0s*qvf tnpd* t(s29 bqjs9mpe. The object’s speed increases uniformly until it has moved counterclockwise through an angle of$55^{\circ}$. The average acceleration for this motion is $9.8 m/s^{2}$directed straight downward.
What is the time for this motion?

  17.38: A small 2.0 kg block rests at the bottom of a bucket. The bucket is spwp -3*k+lhrhoe6 0au* qa ske0un in a vertical circle of radius L by a rope. When theqpeu 0l hrk+-6w shka0 *3o*ea bucket reaches the highest point in its motion, it moves just fast enough for the block to remain in place in the bucket. When the bucket is at an angle $θ=30^{\circ}$from the vertical, as seen in the figure, what is the magnitude of the normal force (perpendicular to the surface) provided by the bucket onto the block? Note that the direction of the gravitational field is indicated in the diagram byand that the block does not touch any sides of the bucket aside from the bottom of it.