95.02: An object shown in the accompanying figure moves igh)eg:m, sdz.n uniform circular motion. Which arrow best depicts the net force acting on the hd. sggm,:ze)object at the instant shown?

  05.31: A child is belte)ymf )3j +u0pfyph8l ed into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total f p)0 8yhyffj)m+pu3 elorce exerted on the child by the seat and belt?

  08.14: A particle continuously moves-2pu)qf ber4b in a circular 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 point Q. Poinr42-)upfbb qe t 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 ifl,9 l t*:hmmcircular 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 point Q. Point Q is exactly half-way around the circle from Pl* hfltm, :9mioint P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves ase)x )/l 17k-gb+0 weveb kyhclockwise with constant speed around the vertical circle shown. Whk- ae1k7ysxgvlee0)b / bw) +hich arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small ;cwgpt0.j7g pz -w: wbmass connected to the end of a string counterclockwise in a horizontal circle above her head. The figure :cw0;p bzp. 7jwgtwg-shows an outline of the mass’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 ar 7w2 g6 2z sx p66s9um9f) wsxeomsjjyv.4ye/sound a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the directiony/sg26u7pm s)ox2smj 4 9 wszvs6xy.jw e6ef 9 of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple gh3x)+ypud n3 pendulum that is released from the horizontal position at rest. At the moment shown in the diagram with 3u+ nd)pg3xhy $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) po0gj 5d 4o lx*1gu73dq xlrxdk7int-like object rests 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 0.50, while the coefficient of xd77qd 41dggolx0uxrj k* l3 5static 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 2lj9/as *g6 g fnnni 8*wg6mqxkeep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface w/6 2gsgg6qw*a*nfx lnm8inj9 ith a speed of 2.0 m/s?

  05.03: What is the centripetal acceleratioxu f 9hs 4tar)+*uzy(bjc5uqhvzlem (+bf:) 6n of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant ratetz+jb(+46f(fzu u9u5s h ce)bhrxy m qa)vl*: of 4 times a second?

  09.24: A point mass moves alo6hik 4 egkx 3ff;)p,d 4t.vocpf-gye,ng a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force actingpo4 fc pk;e dt,xef3ki, -4g.h6 )yvgf on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a8poju9d1s wayqaf7 24o. kbz* horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution o2k9sfy8a 1.apu*j4dq w 7oz bis:

  99.22: A child whirls a ball at the end of a rope, in a unif7 j.u18wc+isvnrs5tporm circular motion. Which 5jvwt 7s.p1 c+nsr 8uiof the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a strinpcs.jjkt.z *3mhr1eg0 0o:v5 m5 tmcwg and whirls it around in uniform circular motion. The radius of the s. w jem m .h3z1pjgoc0*50c5v:mttk rcircle is r, the speed of the mass is v, and the tension in the string 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 pulled outwauess c8,5; c z7nykn:yrd 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 arc. What is the tension in the string when the mass swings through the bottc8 ycsusey7,5;n:n z kom ofthe arc?

  94.15: A car is travelgd4zk8 u h4-pxing on a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills hak- 48x4gdhpu zve 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/;b0 1cxmg lug: urs0/yn:s+rp s. At the very top of the hill, the shape of the road can be approximated as a circle with radius 25 m, aslg;+yxp0bn:/ c 1g:u0surrs m indicated in the figure. Which one of the following choices best represents the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant speed. k ci6m1cof9u: The magnitude of the net force on the spm69fo ciuc: 1khere

  11.47: A simple pendulum of length Lhasa point mass ;flphu at7;t*hc ll)-M released from rest from the horizontal position shown. In the absena)tc7;u lf h *t;-lhplce 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 gravitational 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 string forms a simple penduq; j-;m32o0nvg uhegclum. The mass is released from rest and undergoes simple harmonic motion. Which one of the v0;-nu;h2j g 3coegq m following choices correctly ranks 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 t3, ef4 jbvh6d( /tr 5fnevey95.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radiube/6t 5 9envhfyt,34ef (vrjd s is made smaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected 3ct2lt-ade 1 6t, iqeeto 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 sprtlqia3 t, tc21e-6ede ing is extended 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 m oa9b.:gpbidc0u33eqew ,*x a 4.0 kg mass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net forcxu*.3c qepdg 3m,ba0:io9wbe e acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal di 3js /.sguvkl z:t/-yosk rotating at a constant rate about an axis perpendicular to the plane of the disk and throu:zy sgu v.s-oj/3ktl/ gh 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 of string and movesns 0xd66fpy(j bx4li 3 about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string0sd4x n(pjx6f b3i y6l 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 is in uniform circular motion as shownxp*8; i xxuooi9 d+a9h in the figure. The string to which the mass is attached has a lea; xoix+xdoi99h* pu8ngth 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 ft d4v:33qnit k -2e.d asx7kdjrom a horizontal disk’s center. The ddq kka4t.jt3 :s di x7dn-3v2eisk starts to rotate from 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 mass M = 2.0 kg is attached a distance R =1.75 m fro;3;emwa p p0mzr0p+*/*zb yexvh+ hmem the fixed center of a disk as shown in the figure. The disk startspe+;pzv/0**pwmy rm 3ehbza h+0xe;m 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, wi au-c09o 5 rva:z87fh)sfgtw uth initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise thro0 u h9 uf azgv5ro-w7aftc:s8)ugh 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 circ.ih3hv( qhh1v/uhp 1qle, starting at the top, with initial speed 17.0 m/s. The object’s speed increase(u h3/q phhh11i vqv.hs 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 restslkouua1p12 belc2 klr(6mx** at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just fac*2p e1l1ok lr bukum62(xl *ast 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.