95.02: An object shown in the accompanying figure 1abq7y1;ne iomoves in uniform circular motion. Which arroo 1y7qa1eb ;inw best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris W3ecm*v4 du 8qcxbu ;9.aqy8xdheel seat that rotates counterclockwise at constant speed at an amusement park. q 9xcc xm3* yvea;8db.48qudu At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circ7md))/v )oq z fp ;87iaidoosjular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves s odqjim;o8ai)p )7f)/d ozv 7along 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 auchlyu1b-:z)r:e( ry hp pn,. circular path at constant speed in a counter- clockwise direction. Considerpby :.,h(ercl1h-y zp nuu:)r 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant 5eq g5lupjm+rmkd*bb1 v-p te7(q4q)speed around the vertical circle se*je5rg(- 7uq1 4 mq bv+qdlbp5t)kpmhown. Which arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mami( ksv.ewbjlx1 430gde *5onss 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 point5l41bexdekg s.mnj 0oi3 *(wv on the path should she let go of the string?

  15.23: A car moves with cop 1hg (/wbgwq(.yvw 5cnstant speed around a horseshoe-shaped path as shown with the arrows in the fiw5gbw/h(. qcw y(vpg 1gure. Which one of the following choices 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 simple pendulumxxrdz 2-f d1l2 that is ref d2z1rd-x2xlleased 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) pointr+d(8esz a3+pfp ne 2t-like object 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 frict ar+ p(+2nf pd3t8eeszion 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 circle e9hcvp yz 6 /y9c24phkof radius 0.5 m on a hori/9 v9ypchep 26 4ckhzyzontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accelerpp-gw- d kt7to ckp0s7 -/qwb0ation of an object (mass = 50 g) on the end of an 80-cm string rotating at a constanwgw t0p7 tdkkp --p0-os7b/ qct rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radiuglg3,r3 8p/6yaqn.+b mnng m fs 0.8m with a constant kinetic energy of 128fnga/qn. +3y6nb8 r3g pm mg,lJ. 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 ib gq ghziu j:90l*zz82ae *5e :ckg2fun a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during eachz kqubga 2gu9*ge *l2:8izz:jehc0f5 revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circular :3ssk9h,7 rs auqwybfw+.uuw+/ 4to qmotion../ssuq 3u4a wqu: 7br o+9w+khf ,sytw Which of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft at2;2vhdh 6gquwos cl; p(.txquh( jy31taches a mass m to a string and whirls it around in uniform circular motionc36(x ud2hov;t(p hgqw;. qju1l2hys. 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 circular motion would be

  07.22: A mass m is pulled outward until the string of length L to which it h ()juqh/i7cx 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 the mass swings through the cu(hq7 /)hix jbottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the rigm5 sy: 6p4axhi8r)ey pht. Assume the car has speed v apyshaxm54y e)i:r 6p8nd 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 a hill grgylm7q2 6sbz lr3ejbc(,74 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 i2g cs7lm 4re6y7qbzl(b gj, r3n 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 inspxupw 5;2ni4 a vertical circle at constant speed. The magnitude o i pup52sx4wn;f the net force on the sphere

  11.47: A simple pendulum of leng6btq (8efjp 6r b5swaiez *02gth Lhasa 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 ma8b ep*6( sz5tb 0g2riwaj fe6qgnitude 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 (point P)?

  16.32: A mass connected to a string f 5ieu jfk*)6jrorms a simple pendulum. The mass is released from rest and undergoes simple harmonif5i6rkeu* j)jc 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 5.7p3hfeqr yzf h6vy0r9n m8 1.d0 newtons is applied to a rubber stopper moving at a constant speed in a horizon06yvfyr3nmf1phr hzd .e7q89 tal 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 surfagt-jaq.l7gctov 0 :4hce, 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 applyin4atlj0cv 7hqo-.gtg :g 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 massl trxn9*46zc65gw x;y. h8fpmmojh8 c with a constant 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 4czh5y 9w x t6omfnj px8r;l *.86hcmgpoint of the circle?

  14.23:Two small identical coi+j ccfg7p t7 )sp ,dqxngs 0gmq/j+t80ns (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its cente0fp xqgtc7gq/ jj)+t cmdnss+7p,g80 r. 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 a k 9bc;.xu-qkf6xei*h bout the string’s fie6u ;xix- fhqk.b9 kc*xed 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 an angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform (e92bqthsf-ff ek 5o ;h:w4-k *s vuoccircular motion as shown in the figure. The string to which the mass is attached sk5o-;2fqwoc-v tb9kf4u: sfh*eh (e 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 v :0hqga7 3ttw cx0s8:ib-jxeis at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest abouxic- 3a0w 8 :x:sejq70tgtbvh t 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 at+6c- 9emb hb 6kg)dupvtached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starucpk-vhmeb6dg 6+9 b )ts 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, s6oh5g;ifayzxsrl,t c837 mex1ng 5( ttarting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has mrx63gc ohny7a51gmst,fl ie 5x(; 8tzoved 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 ixiin4i 8 s5t8gi6at a5n a circle, starting at the top, with initial speed 17.0 m/s. Tnt85 gi8sai 6x54 iatihe object’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 bucketaxdp6-(cyhi po91 p: v is 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 buckxy piv1a:-o cd ph(69pet 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.