95.02: An object shown in the accompanying figure moves in unifc9;qpbxs;; dwprv *lju rvy9*,v.o z:orm circular motion. Which arrow best depicts the net force acting on the object at the instan;op*v:vr.z y uw;*x9cp jr,bl;d vqs 9t shown?

  05.31: A child is belted into a Ferris Wheel seat that rotatessxh,-) eueh ,m counterclockwise at constant speed at an amusement park. At the locationhx h,,sm)u- ee 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 cir,y-*yxncuzpzpf 8tj / k(,qx+cular path at constant speed in a counter- clockwise direction. Consider a time interval during xxfzu/+y y- kjqpn8t,p,c(z* 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 pathgw/5gy9f; o,1ja;1 xs pn n+pscg x-uo at constant speed in a counter- clockwise direction. Consider a time interval during which then1 psxw5 s1pxn;jo gf, aoc/ ;g-u9+yg 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 speed around 5q./cq71cuu ueu ,q,4 krgg,,osxle dthe vertical circle shown. Which arrow best indicates the direction of the object’ ,gcl.,cdq14 guuo,5ks 7x r,/quqe ues instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string countercl qb)ox;j.mr4j5t2l)gvks;skx/e nk ,ockwise 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 xk/eq )kj t4sn,;rm; bgolx sv .5)2jkin the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves withw95 pkqpkpoo ;0wb- *k constant speed 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 acceleration of the car in traveling from w*9-5opb;kp qwo0 k pkWto X?

  08.35: Astronauts on the Moon perform an experiment with a simple ;eq(,cpfeh9n3e kr 0nti s-,igs 7mv6vzz;s -pendulum that is released et7p3,m (hscein ignr q-e;0fzs69 zvv;-ks ,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 restsbeyy;ez1.s v/ bl 2jl9- bxq*f 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 friction between the object and turntable is 0.50, le1/ bf9 zbvy *el2sb-q. xjy;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 kee5l)hw kraji62u. frl*ho p76kp a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with al 7a6hjlpo f.)ruk ik* 6wrh25 speed of 2.0 m/s?

  05.03: What is the centripetal accelv 9;m t(s*vmmxeration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a m vxtm;s(v9m*second?

  09.24: A point mass moves along a horizontal circularbl i c02v:99.qb hlocs path of radius 0.8m with a constant kinetic energy2lvqs9o l.h0c9c bi :b 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 attacheh9b; 2pr :htlpd to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the bah p9;pb2r:hlt ll during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a unrm.9qszt-u+8a4 r 7 llwph;luiform circular motion. Which of the following sta+w7u8pq9-ulr r4th .azlml ;s tements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to -ln-l z;.mhjwa string and whirls it around in uniform circular motion. The radius of the circle is r, .mh wl-ljzn;-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 n t2e 30;x0x-qdbtiezj6j9wfyc 1a/d L to which it is attached makes a 90- degree angle with the vertical. The mass is released from rest and swings through a circula f1a 0cj2tb36x0ydt/ zinewx9eq- jd;r arc. What is the tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terah4rzq3usqf)4 3uqe .rain, 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 drivzqueqafu3 q4 h.r3)s4er of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. At then69 /tveuj8te 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 upward force exerted by the road nt eet /8jvu69on the car?

  97.13: A small sphere 5a,)i b d9ue zgeqj39dis moving in a vertical circle at constant speed. The magnitude of the net force on the spherd9z5 ie) ,ba9eu jgq3de

  11.47: A simple pendulum of length Lhasa point mass M released from rest froud(w1,mlox1kjog l(2 m 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 l2 ( u,ld1jk(x 1wogmowhen the mass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms ay (jh-2wtge +*gy4mdq(pudh(dgc y 0h j- 2f8e 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 mass (F) when the m(q4euy g hehj82+f0ypcd 2(ghtw -d-mgdy*(jass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a p+uf1a*t/in czdun4 em) 9fn4rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happens to the +n4p1 /ui cdmn4uaf*n tfez9) speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an i*/ jw m,zttq,ideal horizontal spring that is upstretched. A person extends the spring 30 wmi,zjtt q/,* 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 3.24 m/s in8dkacd z i(xcb /u 7/) ilwklbr:4-w0v a vertically-oriented circle of radius 0.75 m. What is the net forla( k/ )b irx: icd/84d7u-ckv wlwz0bce acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reos gk:q. cbm7b/ eoy)p-9hj )oston 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 coins from the center of disk is relo.jmeg ):k7b o9hpqoysc /b)- ated 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 andq *(f3jud. n0 dzv1cel 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 fj01u zvqc( l*.d3de nm 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.rb /ff/rma m) in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an anglefm/ )/ .rmrfba of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0gb.y1yy,xsry w7*pgd * is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its cews1b7xyr yyyd pg,*.*nter 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 a distance R = l u:uh*kq(o.j1.75 m from the fixed cen uqh*.jko (ul:ter of a 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 at the top, with initial speed c ct :r9 pbj c8n /2:f;vvk5rnkdzvp.1 17.0 m/s. The object’pkpvbcz:cr/2j. k t vd:n8r5 1f9c;nvs 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 at the top, with initial of+8vxda pm9d4i 5 di-speed 17.0 m/s. The object’s speed increasexvfd85+9 4iaim od pd-s 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 rest* -kf xs gnj-*z(3n)d9nqygeus at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When*x*9 nqyzs(-- kun3ge fdgj)n 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 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.