95.02: An object shown in the accompanying figure mt- as1b ss hruav92)3ioves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant s 3b s9)va-asrhtis 21uhown?

  05.31: A child is belted into a Ferris 1yv.d jst*lr4 *0hzxeWheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best rejed1*r0 *z4xvh .yl tspresents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant speed in a q(9jmm+ e5d zmc7lq /jcounter- clockwise direction. Considerz 9l57j c/(d+qm emmjq 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 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 consrh(i;9 dyqk8p tant speed in a counter- clockwise direction. Consider a time interval during which the particle moves alo(dq9 8;hkypi rng 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 acceleration during this time interval?

  15.07: An object movct(l8 gqfk9ashs2, 3pes clockwise with constant speed around the vertical circle shown. Which ash2lqf(c3kp tg sa9 ,8rrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass yg.h4 5jbl3ao connected to the end of a string counterclockwi jl3gy.b4oha5se 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?

  15.23: A car moves with constant de vjw)c2-0m mhl+9ftgcjb4 7 +o; tmhspeed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleratetmv 7gdh)b m +4+-t0ocj jhw2cm9;flion of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an exlg ;jlfk8*mbu94 u/ufperiment with a simple pendulum that is released from the horizontal position at rest. At the moment sh4 8uukf l*gjf;mub/9l own 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 centt;czmp5- b.bc by/ qcin*ph mqp-8*1 ker of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 s; qyzpm. hc-i- mc q1pb/pcn58b*bkt*econds. 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 keepcd5(3azf htw0 744seyi.mchz0nl1hz a 1. 0 kg puck moving in a circle of radius 0.5 m on a hor0cehsc wyhia1 7lt 0 dnm35z h(z4fz4.izontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centrip 2p-cum asdx2eu6gj:x mw: ,2zetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a co2 e xx-su2a: 2gmp:jzmw,c6udnstant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path osze s9pbvy4oq1gtyw3+uaa 3 fdk 0(+.f radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net forc +4 osadg1e(y bf3zpvtsu q+a93.0 ykwe acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and w mk53j+1 avcshhirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during eachcjsk5 13v am+h revolution is:

  99.22: A child whirlsr46 iw wy:z0do a ball at the end of a rope, in a uniform circular motion. Which of t 0o6w4rdzi:w yhe following statements is NOT true?

  00.19: An astronaut in t/ / t.igoqbhq*5)efban orbiting space craft attaches 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, /5gh eb*tq. /tqo bfi)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 ( u7ig8p m+wy (j +pqkfidq(p3string 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 tensioni(fyudg+(pm+8q pp3k i wqj( 7 in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road c3./pvaql jg*in hilly terrain, see figure to the right. 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 a.lv qgp3/ c*jlikely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. agx6u(ns* 3rkAt the very top of the hill, the shape of the road can be a3xka (* 6nugsrpproximated 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 exerted by the road on the car?

  97.13: A small sphere is movi,jtv;tt l;m,7 ai l0vrroc3c:v*x dd+ ng in a vertical circle at constant speed. The magnitude of the net forl od,*x:mc7jr iavctt0+; vdr,;3tv lce on the sphere

  11.47: A simple pendulum of length Lhahhmv47 8m: a-qt 3bzwgsa 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 gravitational force acting on the mass by the eart4:whz- 8 ht3vam mgqb7h, 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 s m1sdk)q6 txm-imple pendulum. The mass is released from r kd)-sm6t1xmqest 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 the 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 mocikxr0 -qrp8vckx ,n+;(0bl)b a ppq( ving at a const)i+0 b; k,xn(aq(- cxprvrqpkcpl8b0 ant 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 stopper?

  05.28: A mass, M, is at r qqkb; uq7-m+mest 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 sprink;b-qumm +q 7qg 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 wi ,3dj8m:uzfs3g jcs5jth a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What u,dj 3mjssg:zj 85f3 cis the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X and ntzo72 u,-pncY) are 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 coino, 2zncpun7- ts 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 massd yh.v--dpou1 is connected 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/duyv.-o1 h-pds. 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 uniform circular motion as shown in ;jv:inz/jqm+w.s808 lv5ofbpk 4r epthe figure. The string to which the mass is atta0vj 8k+ 5.bz;vo i:qf 84wjemsnp l/prched 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 ho,ln bw+)g1te*ywhon q ,+lkupi y ;+2krizontal disk’s center. Theqwlp +ky bg1,+; kiuylw,+nn )het o*2 disk 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 i i6unxia:*r) ,fqbw 5/6ampibr4sl :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 b66fmi,/n:aqrw) 4si lxi ua:*5ri pbangular 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 initial specmnq,axtjd7c 8: qw; 6ed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throu6 t xj8c;dwcmaqq n7:,gh 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 lg,v +s+j4bjda+ cow;in a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases unifordwb ;,+a+sv jj og+cl4mly 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 b8.y jhjlmnazpz/0x t+ ccq-ag kn75 vo.-+dm+ottom 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, za+ -yl nd+5j8.vcx .to7pazhj- mcmn0 +/qkg 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.