95.02: An object shown in the accompanying figure moves in uniform+fbr:009btasmxg3 8znkrh+ v circular motion. Which arrow best depicts the net fo:m8ha 3+ztrbf0kb svx0 +grn9rce acting on the object at the instant shown?

  05.31: A child is belted i t0(gu+h dyp j1h2fp(bnto a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direcg2p uh(f( yj+h0p1tbdtion best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a rfgh*kzva f/82::tc gcircular 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 fg ac/v:*rh:z2 ktf8 gpoint 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 constant speed in a e *z +2rqz+stb2hdqk/counter- clockwise direction. Consider a time interval during which the particle moves along this circu sbed+ +qzqk ht2/*2rzlar 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:/2iadz )jdx m constant speed around the vertical circle shown. Whid2dm ijxza/):ch arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string1f hdcc/ jl1a90wz-eawa0t4 i counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path ltecw /a1f d a00w19z 4haic-jviewed 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 as5 gqd* xt0fd.lz67n dh shown with the arrows in the figure. Which one of the following choi7g* z5xtdf6ld0dn. hq ces best describes 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 zj)6k3 o1ujk1 a(hkjksimple pendulum that is releask1u6jko(kzh) k31jjaed from the 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 from the center of a 2yw0)y3m6nae pqkm/jui; b 5crough 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. Whynw)q m5i;yc6p3u/02mbkj ea at 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 cw7sl7pv8j6 jsircle of radius 0.5 m on a horizontal fric8sjw 6jls 7p7vtionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleralp(,fktlk8-j tion of an object (mass = 50 g) on the end of an 80-cm string rotat l(kt,j8-flpk ing at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circte0t1l q3 u6jcular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mastt1q6 ce0jlu 3s as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string 8n5 7 kr qashc+g)7obyand whirled in a horizontal circle at aq7ry5c8 hsk+ ban7 go) 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 ball atox0;81y yuu4 :bpi 0xvuq,h uo the end of a rope, in a uniform circular motion. Which o4x u vyyuo0 pu:xou;8bhq10,if the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass t* hkuda wg5/ .k- zofvu51on0ifbe:/ 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 t*ont5//ouaf0bh z-k gk 5 .duw1 :ievfhe tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the()) *lu:f6 xpwl chpjs string 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 tension in the string when xlsfpu( :jlwc)p*h6 )the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure tone0hjpi4* 3lp qd 5j3o the right. Assume the car has speed v and the tops and bottoms of the hilpqn3i5 d* 43jplo0hjels have radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over aeb7uoyx*8*ih clgank r -23 *z 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 indicatedo* lex*ig-czkrn h7ua2b38y * 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 moving in a vertical ce1 vpr ,9iscby* kj,2q3p zfd,ircle at constant speed. The magnitude ob 3i jq2,*,vzsedy1k ,9fpcp rf the net force on the sphere

  11.47: A simple pendulum of length Lhasa point ma 6u1:phch6se/i gfr3 qss 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 earth, and F represent the magnitude of the net force acting on the mass. Which one of the following choices descr1egqshf:pi/u66 h3r c ibes the relationship among these forces when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connectech7noo6+/+ avu+v iprd 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 string (T), the gravitational force on the mass (W), and the net force actu7 v+6+o+ pac/nroi vhing 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 mxfvh6 1y1k4 ahoving 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 hyv1xk4f a61hfrequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surfa ;ds/,yfg89th u *j )fri9bkmfce, connected to an ideal horizontal spring that is upstretched,dk m89hgtr)*;fjuf/yfb9is . 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 speed of 3.2kfaj8nv565w6g um , ka4 m/s in a vertically-oriented cwu j,v56afk 865makgnircle of radius 0.75 m. What is 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 an5bb+d 1g1sx;cu*qd g- wd6 :zj4ptbq ldY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the d* gl dpj64d1b wtq1 bzq;c+udx-s:5bgisk 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 of string and moves aboft x(p4k,pw v9ut the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The str4x(vktp ,9pfw ing 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 cir;z145tj 7me ei8hy qkecular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angleizyth4e5;7 k8qe ejm 1 of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of massf5fm 0;gq/ awz 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about ;0azffwq m5/g 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 ic1fn6ge3 +bue(ekdyu4 xm/(us attached a distance R =1.75 m from the fixed center of a4b/ n(g dxe6y(uu ce 3+femk1u 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 ar9b97 .bnz uhcdoa6j y( 7yz,qt the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle oay.9 zyqhdj (n7u or ,b7c6zb9f$55^{\circ}$. 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 topav5t :9htwhmxa ,- m/n, with initial speed 17.0 m/s. The object’s speed ihx/ :, t5-nmamhtvw9ancreases 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 is sg a,e0zs.5ws7;zksa zpun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it movessaek5;.7 ssgazwz , 0z 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.