95.02: An object shown in the accompanyinprff,pigz6 b*vks t ,v/ h-k4*g figure moves in uniform circular motion. Which arrow best depicts the net fokf*vtp6/shvp, *z,fb-ik gr4rce acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counteri tzbpovf,v397fi.2n clockwise 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 and be v.,zvti3 p 7fbonf29ilt?

  08.14: A particle continuously moves in a cijk90- -c bnnnba ;o9b3v3lhglrcular path at constant speed in a counter- clockwise direction. Considkb 03bv-h 9blan 3g9cjlo n-n;er 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 pao+k-y+lfg*e9q c5p4qhmmox :th at constant speed in a counter- clockwise direction. Consider a time interval duryq xcq 9 k*o+of g5mp4m+leh:-ing 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speep9v fxu;u*6rs d around the vertical circle shown. Which arrow best indicates the direction of the object’s instantaneous9xs;*f6uvp ur
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end /(yrtdo+bv u6of 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 ofr+y6td/ b ou(v the string?

  15.23: A car moves with constant speed around a horsv.(4ih af0q5o f ru7oxeshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration qrf i ouv af4(h.7o05xof the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pem, u -y k8xn/oj1b5, ee/xsmtindulum that is released from the horizontal pxmj,8y sn/o,-k5ie /xbu mt1eosition 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 fidli;.y5o+enxs4cimm (o )y 7 rom 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 magnitude of the force of friction acye sx( 4)o mn.o+ciyilm;d i75ting on the object?

  07.19: What net force is-y u4n8oyia92/ czy uq necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.4un qyauy-o2yi9cz8 / 0 m/s?

  05.03: What is the centripetal acceleration gq 8/(8 zfa:d t8sjctpof an object (mass = 50 g) on the end of ands t8j8qat8f/ pg:c(z 80-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.vejixr, *ya: .5owe w48m with a co :x4*5v,oyw wir.jaeenstant 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 whirle b(if*gej 1a0fi6-ms r ju anlh.8)j1jd 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 each revolution is-ajb(f1 e8 juj *jl61ih.rfsn a)g0 im:

  99.22: A child whirls a ball at the end of a rope, in a uniform cll 49bpo82u bdircular motion. Which of the following statements is NOo94 l 2pblbu8dT true?

  00.19: An astronaut in an orbiting space craft attaches a mas ) crr/cj;xv1bs m to a string and whirls it around in uniform circular motion. The radius of the circle is r, the speed of the mass )cc1/ bjx;rvr 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 i 2l.rmni )4 ic;br.oljv8b5f ut is attached makes a 90- degree angle with the vertical. The mass is released from resf;v4 bu n.r i)rbiomjl8.2lc 5t 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 qs)e- 5ctwm9(2tpp4 ya -jtxson a road 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 l spmw9yt52pc4je sxt(-t-a)q ikely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speedeau) 0mg7p r0x 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 represents the magnitude of the upward7x0geu 0a)r pm force exerted by the road on the car?

  97.13: A small sphere is moving in a blz; e/vsps4 j7 va,m2vertical circle at constant speed. The magnitude of the net fs7mp;4jba vl e2s v,z/orce on the sphere

  11.47: A simple pendulum of length Lhasa point mass M releaszf5lv0fe( +ct80 cuzy szq*+ned 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 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 (poczq u*(0el 0tfny 8f+s5c+ vzzint P)?

  16.32: A mass connected0kc* ud4.gu ev to a string forms a simple 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 striuv4 c0geu*dk.ng (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 moving tuba*+1konibey 4( w- +uz /xbat a constant speed in a horizontal circle. If the same fau bobkn e1wuti(xyz/ b 4*-++orce 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 4t sl9ruf0/-cq m)t fqii3t9rideal 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 a4t 3 i csq- ri990)rf/qtultfmpplied 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 q6./llzctz 3nt f6g5 xmi*1 yein a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass whe6l y*3t nf i5/eq6.ctlz1zgmxn it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal di1,wm,gzbx zg)go:w9ld4p .pc sk rotating at a constant rate about an axis perpendicular to ,z1 ,owwmgcg: zplp )4 xb.g9dthe 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 connected to the end dhzfbndc ay*,wr .4r/ 2jn4( yof 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 formzbdfyyhj4a,*n d( 2n rrw.c 4/s 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;* apxf80pz 8;bjrwj17vh 54insxfmn as shown in the figure. The string to whi nnv8* 8zb f1js75 p;wmhxfpx;jr4ai0ch the mass 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 mass 11.0g is at rest 30.0 cm from a horizontalaib/ md* btz), disk’s center. The disk starts to rotate from rest ababm)td /zi *,bout 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 kgi:zpuqx7 kk2 q87 .p8+fco4qb u3onfi5 ;ybuc is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk startspu8 x+ku3c ikon o5:4qf 7buf q.i;72 bzyqp8c 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, with initial z (-r+s:wjjihhdg *dgn69ra6speed 17.0 m/s. The object’s speed incgrsjzr6-nd * (g d +jhhw9a6:ireases 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 final speed of the object?

  16.40: An object moves in lqlq0*c+4 a,1fiv l2stq f7pt a circle, starting at the top, with initial speed 17.0 m/s. The obje1c+q la,q702lq tp 4ftv*slifct’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. The bucket i3szvg4ah 7lpurl z 07d.g r c+.w//vybs spun in a vertical circle of radius L by a rope. When the bucket reaches 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 lr7vh.v4auyszzcg7rl /p/w. 0dg3 b+ 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.