95.02: An object shown in the accompanying figure moves in unzj9;7zby y, omiform circular motion. Which arrymzb7 ,9j ozy;ow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belt:ipab k;hp2; hed 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 force exerted on the child by the seat aki;hh2ap bp: ;nd belt?

  08.14: A particle continuously moves in a circular path at const.uk5 jty(wcn9 : yah ;b3uym*eant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to uw hmc(ukja5.ye t;y9: *3byn 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 co wda-b*z;,t lentinuously 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 from point P to point Q. Point Q is exactly half-way around the circle from wl-t*a,be;z d Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves: sn m 5xsz-*vhjt)avgz5 yg3: clockwise with constant speed around the vertical circle shown. W) y *zg xv-mts:z:3vh5njsg5ahich arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass conne d29q8bo /ir+xw0 (paacltti *cted to the end of a string counterclockwise in a horizontal circle above her head. The figure a8x9di2 cla(iqwt p/0o+ *trb 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 around a horseshoe-shaped path as shown wx; gpr6qg*;lwith the arrows in the figure. Which one of the following choices best describes the direction of the xwg*;q g6r; lpaverage acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum that p5 q8 wfy:5cgpis released from the horizontal position atqpy8gw fpc:5 5 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 from the celpe.d 6+w8 u0cqf8xbpnter of a rough turntable as the turntable rotates. The period of the turntable's rotatb x.+ p e8pfq0clwd6u8ion 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 magnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck moving in a circsybngeq-b*4o 9q cu/3b)k pu; le of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/* 3p/; b4kbob yuu9q) cneq-sgs?

  05.03: What is the c*-pkighf *7kzentripetal acceleration of an object (mass = 50 g) on the end of an - *k*kzfigp h780-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m p yq,9s6k(dq lb vz+tbz ,fu);with a constqb;lyf +b,k,d 9st qpz)6uz v(ant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled inf9i pzg vc ;c+s. jv8);ksbr5, 9isplo a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work 8 vvc+ ;iboz,9)l ps.i ;s5rfspjcg9kdone on the ball during each revolution is:

  99.22: A child whirls a ball at the end o9;ki eh4g,j6ai0) kg :4cq vhe;q ohyiwb9yn7f a rope, in a uniform circular motion. Which of the fol6cqj944,; )gbihygvq:;k e i0aneihhkw79o ylowing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m tp/m5yt;zk.lxv 5drd . o a string and whirls it around in uniform circular motion. The radius of they/;l.x5tm dk5rv.dpz 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 circular motion would be

  07.22: A mass m is pulled outward until the string of length L to which it is attua(d) +z ilw+tached makes a 90- degree angle with the vertical. The mass is released from rest and swings through a circular wulzti()+a d+ 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 hicxzkrwl498evy:b m2g48m n0q lly terrain, see figure to the right. Assume the car has speed v and wr4908g zmy:ql8knevbcm 42 x 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 a6 )9 etvrrm;ot hill at a constant 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 radius 25 m, as indicated in the figure. Which one of the following choices best rerrv)6mt; 9otepresents 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 cov/ r5ng:luqfza )n+ex84bc)64mg( sx djc d;ynstant speed. The magnitude of the n8bvj6qfgr)c(n;:4 emz5csngd xa4ud +) xly/et force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from re4tvl+c4 aa1yq:i xl:m pvs51ust 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 gr :l4+ l41qya xvpvt5s:i a1ucmavitational 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 mass4ux bcg1 lt14l is released from rest and undergoes simple harmonic motion. Which one of the foll1lt144lb x ucgowing 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 5.0 newtons is appluqc ftm apvmm;-7537tied 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 happens to the speed v, and the frequency f, of the stoppft 7pt-mvu7 qmcm; a53er?

  05.28: A mass, M, is at rei9vaw11ceq ;fc2t gvqd gwr(.z4 v/c9st on a frictionless 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 extended back 30 cm from equilibrium, what is the necessary force applied by the person to hold the mass stationg.9;vri2t daw1 g( q vcvcq4/zwfc1 9eary there?

  12.22: A girl swings a 4.0 kg mass with a consta+y/8. bicycq5x eqix ,b70 oarnt speed 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 poinq rai c b+yi5 ox0yq/.7cb8x,et of the circle?

  14.23:Two small identical coins (labeled X andY) arfe-uuh q/vrs+xf-.;q zg+e3ke at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the coins from/gq.+ rzuh- se -fku3q+;vfxe 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 0t5guvfe.xvh+jn h.8 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 n8 h .eg0vuxj.h5+ftv 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 shown in the figure2fkj, ) eu3e;n ,ylymatn 3e1j. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of ,3n u;kmajt)fnje1, 3yee ly2 $θ=50^{\circ}$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 horizontal disk’s6tucfeuq4 .c1 center. The disk starts to rotate from rest about 1ut4.cc q uf6eits 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 attachelas ,qtkehs):vg mhgxs7:1 /7d a distance R =1.75 m from the fixed center of aalshxmh/qtks g, g)7s e:7v1: disk as shown in the 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 eldy;9kib;e * top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise ; bdly*i;9ee kthrough 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, w pqubnm ;r795ai :v;dbith initial speed 17.0 m/s. The object’s speed increases pb b;5vurq a9d;ni7 m: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 buckvlk+h61)k p l6vxp 6epih; od7et is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves juxol)7 dkv1ki66ph6 l pp+;hv est 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.