95.02: An object shown in the accompanying figure moves in uniform circula(pl w6aaqy -1vr motion. Which arrow best depicts the net force a(6la yaqp1-wvcting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheeaqi;0vla i3 r* -j.rmcl seat that rotates counterclockwise at constant speed at an amusement piq3c0jrra;al i -*m.v ark. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves iyb2ugnt :uogo:mb(8+ n 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 pointbb:u +2:uong8g otmy( 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 continuousl , iy.-s6t1of jiwsykb/pegj+)w, 2vs8yn/n l y moves 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 froikw-/l j,.sfpgs)/8 soyn6 b1einy2tv w,j y +m point P to point Q. 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 spe2ui1 b3ggz 9-jq xok4jm5s8 oged around the vertical circle shown. Which arrow best indicates the direction osb zi o5g4uk8q -gjx oj3g2m91f the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a scalz 1m +s 3svcp -6uk6s-hj1ymall mass connected to the end of a string counterclockwise in a horizontal circle above her head. The figure 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 1ls 6vhm1s6-ajy3p+szk c-ucgo of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped path asfj pb 7mcds . yw4cp9:s4,qjp4 shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of7bd cyp ,j jsf4w.m:s4cp 9q4p the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum that2u o4* i;kc evgxtz.m)2wat4d is released from t g)euix*4cov;k.zmdt24t w2a he horizontal 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 rests 2.0m froy6ngy sgg rr0k73hv 94v ,7n 4qs* oofibery67m 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 t9b 7vqy r7syrn 6nh *0yvg 7g,3eosk6f4o4grihe object and turntable is 0.50, 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.g, yxp n7f:9su 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionl :,yx7 9funpsgess surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accelerjf,dudpfz.re mom(62stv 7 50ation of an object (mass = 50 g) on the end of an 80-cm string rote7 6 td,5 rsjozpmv0.2d fum(fating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizonx6hkonh9/z f l1x 9 fksgr),p,tal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the n,xh fs6gzokkp9)1 lxf/, h r9magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 *tl efgxs2 5x9m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work5xglsxt2*f9 e done on the ball during each revolution is:

  99.22: A child whirls a ball at s)04dil)du*p ie .aj ithe end of a rope, in a uniform circular motion. Which of the following statements i .l dud))sa4 iej0iip*s NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a s)hw*n-;onydnu874qrm63 cns 1ji ta a tring and 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 string is F. If the mass, radius, and speed were all to double the tension required to mahj4inru )n*3otc8w1nn6sy d a; 7amq-intain uniform circular motion would be

  07.22: A mass m is pulled outward until th-cv f o- 2gwrs14n1tx*p)pk jje string of length L to which it is attached makes a 90- degree angle with the vertig-1oc4 j r-twsjf v 2)p*1pnxkcal. 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 bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the right9f kgvfm/ ./ym f81 nx:xp0p qde*4ohq. Assume the cax0p*mmf/ v 4/p1qdef .h8kfg :x on9yqr 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 spe+n2q*3rc w5h pcq8utked of 12.0 m/s. At 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 t* hr wkuqpq82 ct35nc+he 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. +98.aot wba gvThe magnitude of the net force .vo+bwat a89gon the sphere

  11.47: A simple pendulum of length Lhasa point mass M relees o((weaj5;9w dx3p rased 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 eo5(x9jwr3;sw( epda 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 pendulum. The mass is re 1-x mblr t3arh0+abb6v omn4 lof06+ileased from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude 4brlht0+-i mb nla6m vr+6ooax0f31 bof 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 mr3;muk g -fnt- )c-mpapplied to a rubber stopper moving at a constant speed in a horizontal circle. If thrm-3);t ukgc-p-fmm ne same force is applied, but the radius 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, cowh*l i :8dxvzvv wl)46nnected 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 spriwvxl4 i vvw*:z8dhl6)ng is brought back to equilibrium and the mass connected to it is now doubled to 2M. If the spring 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 a 4.0 kg mass with a constant speed of 3.24 m/s tdfn 6v0sgd27 in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at6ts0g27vddf n the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontavsg -mfh8u/i 0l disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the g-/vsh iu08fm 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 myak-akvmql /yt- ssca6- je9k;l65o( oves about the string’s fixed end in a coni6(/oelt-a-k6s yq;k9l j -v scakym a5cal motion with a constant 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 is in uniforjvm 1 j-g0o8)hd.wcme9a ukc4m circular motion as shown in the figure. The string to which the maoc jvwe0k. d8c-1g)4 um ahmj9ss 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 masha8 an4y cr2fgebk1+ j47as+.zf j0qzb;qot)s 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from re ntf ysq2z4gkc+b7a;r q +jhe) 0.f8jzob4aa1st 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 r)k36yq xd+3nbg6 bqro:g,x i = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant angular acce3 g,nq bbx6+ykxg irdro3 )q6:leration $α =5.00 rad/s^{2}$ 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, wiigdu(-0md t .gth initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise thrm ud. (tdgi0g-ough 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, starting at the top, with initial speb p, 2tm;my5a qy qjz1m.b;km3ed 17.0 m/s. The o1bq,qbzt5kyjp.;may; m 2 3m mbject’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. Thlkjn4 ) fk8i *62a2n1 ccx ow*fs-rpure bucket is spun in a vertical circle of radius L by a rope. When the bucket reafrx82a *p2rsj nn1ow*k6lc-iu) kc f4ches 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.