95.02: An object shown in the accompanying figure moves in uniform ca( n zl3dq4p1 +s y/dryc9vvdt/)r/chircular motion. Which arrow best depicts the net force acting on the object a )yr/a(+v/1qd p l9zn3y4dtc/crh vdst the instant shown?

  05.31: A child is belted into av-1 n m bjsv(-;q9djvu Ferris Wheel seat that rotates counterclockwise at constantdq-vnsvjm-j; (1 9 buv speed at an amusement park. 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 cw,vl +3k 2h-dneyb rg; /mk5z*zzgje-ircular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circew-ek2gj3/ry;,vznzb-l+z* 5dmgkh ular 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 patt8zu56t fspw, h 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 exacp6u5,t8s zwft tly 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 cebg4lx 4 ,cjk;lockwise with constant speed around the vertical circle showeg l;c4xb, jk4n. Which 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 strincv4 r fg;p1)xr d/m9v/1 9csxis2kuz ng counterclockwise in a horizontal circle above her head. The )nrvzxp2s1u/ 1crfx9s9 ;g4m v /kdic 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 wit+u5dt:v 8mllkh constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describe8tl 5vd+mu:kl s 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 simgzlti7( 285vo6jdl jgp7*f hhple pendulum that is released from do fh7vlt 7g(lgji*z5 26ph8jthe 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 o* si9 f 2g rkchcn82a55dh9bhkg) point-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The p r9 cc5 gn*is52hf8dboa2hk9 heriod 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 acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck movinh zpk , hxd+3g7rm/g6hg in a circle of radius 0.5 m on a hohkg z/p dh 3x6+m7hr,grizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the cewj b v.v,aso9mov(a.. ntripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times vswvmv ao .b9a .j,(.oa second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m with 6 p1 wnw6dqiq3a constant kinetic energy of 128J. What is the magnitude of the net force acw1q663d ip wqnting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled fv ,dsa*3/olq in a horizontal circle at a constant speed of 6.0 m/s. See figure to tofl 3,dv/qas *he right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a roperzw;i7dy-yr05t.yk w ,0fho :tf 4twn, in a uniform circular motion. Which of the following statemitrrt4- y7,0y.oktd5;wy 0fh:w z wfnents is NOT true?

  00.19: An astronaut in an orbiting spajbcbax0 h qv6q/ 9)q 8ay)x6+fo4p,rtp: ghvice craft attaches a mass m to a string and whirls it ar b oya hpr4xf:6h8ta)p9/cq)g6 0qvb vqxji,+ound 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 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 atqg3,mtu,3ohoj*f-cj j f 4 y;wtached 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 4wfhomj o;y-3c3jfuq g , ,*jtthe string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road iqca1n : ecsi34 -1glddn 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 likely to fee cc g1q:n3ead-4lds1 il weightless:

  17.10: A 2000 kg car moves over alb kgwk6,sl2 g0;+gxd q-s n/o hill at a constant speed of 12.0 m/s. At the very ; sw2s0nd6 bl,l x gq-g+gkok/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 upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at 78lj;8/hb p7eo .yji t;rrmzqconstant speed. The magnitude of the net force on the spljq ;ye8j tm.8p/h;iro r7z 7bhere

  11.47: A simple pendulum of length Lhasa point mass l37q;wl(l 8 kmjxyy69o(+)xohreo h bM released from rest from the horizontal position shown. In thl qoh3yor 89e ybk7()6mho;jlxw l x+(e 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 (point P)?

  16.32: A mass connected to a string formst7y.r-8 igdj f0y.w bd 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 acting on the my7-t.di8f gjbw.y0d rass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper moviz anufj h3082xng at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happaj82n 0z3fx huens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at .hfr n9*bv (xd z37n oeqo,me+rest 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. T+o*( n mr,oe9qxbnd7vhz3 f.ehe 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 cd6.qd) iv r uj:g3hxn8onstant speed of 3.24 m/s in a vertically-oriented circrvh d8gjd6q )3n.x: iule 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 identical4,j:4z r8wwyhld fe- i coins (labeled X andY) are at reston a horizontal disk rotatin he,j4f4-d w8ri:lzwy g at a constant rate about an axis perpendicular to the 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 of string and moves about t/o95fi x xjwlp0:j i6jhe string’s fixed end in a co:9l/xjjii6 jxf05pw o nical 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 g9n va42whcsa3g o9 o) k5*)rqaav)wcis in uniform circular motion as shown in the figure. The string to which the mass is attached has a lengta9vscw*va w9 raac4)g5oho)2gqkn3)h 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 revl2hkqo 8v d28st 30.0 cm from a horizontal disk’s center. The disk starts to rotate from resq8 v 282ovkhdlt 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 kg7nvwfokp0t 8 8p : ri+*:lfuli is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest :80lrio vpfk+*8wlt p:f in7u 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 ykcqdp-(u;j1y - :gaxa sa+l8 in a circle, starting at the top, with initial speed 17.0 m/s. Th:k8;lx a1p-caqyysau-j + (gde 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 final speed of the object?

  16.40: An object moves in a circle, starting au*g jjp+xl/i)z;b;w at the top, with initial speed 17.0 m/s. The oj+wg ;i/)j xazpu;lb *bject’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 zdwc 5v2y: j:obottom 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, it moves just fast enough for the block to remain in place in the bucket. When the5v2 :jzocy wd: 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.