95.02: An object showa-ji,be pm15g3s su). bty,kf() pnmjn in the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant s. ugpkaj ),s15( ,mp jt)ynmb3ebsf-ihown?

  05.31: A child is belted into a Ferris Wheevn+-6bge:0fzse ea1kz ggk 259 ql 2hnl seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which - g0k5g sz ehfl2:kg eea9+n6nzvbq12 direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves inxbryl sz3 zg9z7 0.vb9z6k-gk a circular path at constant speed in a counter- clockwise direction. Consider a time interval duringzv ykg9krzz .lb03zg69sx7b- which the particle moves along this circular path from point P to point 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 in0 823wg d8ojrozw2ien a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circoi gw8320zjdre82 wonular path from 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 speed around :ex l89ii80itxl:t r v l4g-hnthe vertical circle shown. Which arrow best indicates the directiv0l9ilein t8lg8x- x 4:rhi :ton of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small q3raxtr)cm lkb ; ;6h3mass 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 go of the string? ah63xl;)btr; krq3mc

  15.23: A car moves with constant speed around a horseshoe-shaped path as shown 4x zeyp54i1 dc)m7mmz01f ffiwith the arrows in the figure. Which one of the following choices best describesf101m 45ffm7 c4zyedzx)pmi i the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a sisg15bd ;w;fy06p7 jdsk.tfo *c.axep mple pendulum that is released from the horizontal position at rest. At the moment shoopy0d7e; .a w p;ssd615bft.kfg * cxjwn 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 objeypm5 s 6ussl)8 oyj-7yct 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 static friction is 0.80. What is the magnituyu756 sj8so s-)pmyly de of the force of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck movifk-mwb -0uv1bx d f6 2 16;zdwaxxrs-b1bv4pung in a circle of radiub dr11b uw6x a1vf bx-msz-fp4bk-6 ;dv20 uwxs 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripea6 v4ez+ hnern:(-eowtal acceleration of an object (mass = 50 g) on the end of an 80-cm str(vherw+ :an64ee-no zing rotating at a constant rate of 4 times a second?

  09.24: A point mass moves p;svhk, t8o9s along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. Whsk, op;t9vh 8sat is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached abov j4n3-+ 8p8kxq yv1/uvknto a 0.80 m string and whirled in a horizontal circljx bvv+n8 qvn8koayuk1p -/34e at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a )(;0x/bj9esxgftywpbyo :9 p ball at the end of a rope, in a uniform circular motion. Which of the following sbby:pefp tx;xgy(o9j 0)9/wstatements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches9l7tydo )g0f o a mass m to a string 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 maintain uniform circulardfgooy70l9t ) motion would be

  07.22: A mass m is pulled outward until theqvgul-,rp65wmtm ru6 1*+l s;5p csix string of length L to which it is attached makes a 90- degree angle with thtrm r gl,xcv 6w u+1uspsq5 -*5;pim6le 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 bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the right7sx q-3r8 jthf. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of the car is most likely 3jfh8 7x -tsqrto feel weightless:

  17.10: A 2000 kg car moves over a hill at a cou2 :;kjc1i6l eaeh5/tbo1la a nstant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be approximated as a circle with radi6: lak 152bhluje oaec;1 t/aius 25 m, as 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 movinds(( ng yzky0byk/xg-9: p 4d0geh;meg in a vertical circle at constant speed. The magnitude of the net fo- khdszgn ek0 0:d9gyyym/4g(xpb e(;rce on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released f/ucs m9+dajp y0br) q:rom 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 gravitational force acting on the mass by the earth, and F represent the magnitude of the net force acting on the mass. +udj yar) qb/:9s0pcm 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 si zy/ aui8rn*m1i6n/tlmple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the 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 t6/ina/ nl8 y 1m*urzithe mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper mot-ji gsy4b+d(th z4yso9 q. *hving at a constant spesbh. ytjt +yoiq*4 d9h gs(-z4ed in a horizontal circle. If the 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, connected to an idea.2ictoifpd rc2m2 bno (r4k:;l horizontal spring that is upstc;rr22ok c.:t biio 2n4(fmdpretched. 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 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 speed6ljtgqa82v8 c of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowest poin la6v2cj8tg8qt of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontalvknt7hh+ ,2i h disk rotating at a constant rate about an axis perpendiculah ivh7ht,+2nk r 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 connectr./m*oma sf0q+( ai0vwy7lfxed to the end of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a length of 2.50 m and forms f/l.qx +0ao 7r*s wmimv0yfa (an angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg masfvf:fj:z qq5435aqg ms is in uniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m andvaq m4fgf5 f:q3j:q5z 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 inu,bqw),z; .3/c.n kwt lw yaes at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a lqze3n ;n)/.wtbuw.w k,acy,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 n j8kulf3-j1dkg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating 8u-jdn3flkj1 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, w p u)rn7vqlotvza1f6i,/ )u n7ith initial speed 17.0 m/s. The object’s speed increases uniformly until it has)av7uznq o61 vi )7lrn,tpu/f 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 final speed of the object?

  16.40: An object moves in a circle, starting at the tvb :/4j7uulmd.x s yg )6slpk)op, with initial speed 17.0 m/s. The object’s speed increas)dx mkjp):l/4gus6 7.v b lyuses 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 asc-k+t1htj c70hu v .is9hyi4 bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point icv7cihjs4 0+hs .ty h19 itu-kn 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.