95.02: An object shown in the accompanying figure moves in uniform *(jc9: z-7f0iiw.ptrlf raro8x :s h hcircular motion. Which arrow best depicts the net force acting on the object at the instanaz thp9r7xli0wo fh:- rrc:f*8 s ij(.t shown?

  05.31: A child is belted into a Fe*q,0uqilzt qs c6 5ow9rris Wheel seat that rotates counterclockwise at c* l5iqocuz960qt ,swqonstant 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 wf(rkw )ycn4fz3 jn8n*w 2:fja circular 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 point Q. Point Q is exactly half8nr)fc2kf 3wnf(:4 jw z *nywj-way around the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously3::u aarqhugx-b 1hr- moves in a circular 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 point Q. Poin-- :ha rg3 ur1xbauqh:t 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 the vertical circle4kyx6u;j 8 nma 7zohu- shown. Which arrow bezuh -jm;unyox4k8 a 67st 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 string 05bs:qw6c*vyuf,kq. rvos/t 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 th0/qt.6ycrusk:5q,v f wbsv*o e 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 pr 7bfrxn u/;x,3f huh)ath as shown with the arrows in the figure. Which one of the follhuu,rhbn/ fx 7 ;x)fr3owing choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on tczk h4z6dt* (fgha6 c3u-twf /he Moon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagram /td cw *6h( h6gazkuf4-3 ftzcwith $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) point-liken +m he.m ,(jy2wdo8t )ai+iis 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 fd)h.s a2tew m +i o8j+iyni,(mriction 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 kee. f jahfs06ku8p a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?fau.sj68kf 0h

  05.03: What is the centripetal acceleration:tkd0t(f f5)e whofx9 of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 time :of fdkw5t0etxh)( f9s a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8/zkiqguf s d,4fs7t4 5m with a constant kinetic energy of 128g/qzsu t 47d sk,45iffJ. What is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball isy0n*fclf 5 sfx,,jy e* attached 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 *eyf,fnxy5lj s0,f c *the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a un58koc5 xha+z ziform circular motion. Which of the followinkah5 8oz x5cz+g statements is NOT true?

  00.19: An astronaut in an or 4sn63kt *wub7bv c.i( voy)ahbiting space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of the circle w )k3*b vo7vuys 6t(bcah.n i4is 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 lengy7p e,4g-vxh ismrqb9l 8q c629of)oith L to which it is attached mio ,msx9pg)v8ce6r4 qqoib7- lyhf29 akes 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 bottom ofthe arc?

  94.15: A car is traveling on a road in hilly yvo:t.o4d*hq terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills hav4q*d vho .oty:e radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car mom+(gsh m2c bwjj03sv* ves over a 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 indicated in the figure. Which one of the following choices best represents the mvmh +sgc3b(20w * jsjmagnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle adae*o 7: w:7 jsb96lf vivq2qnt constant speed. The magnitude of the net force on the sphevb: l dqn ewf* j2i:s97a76oqvre

  11.47: A simple pendulum of length Lhasa point mass M released from rest fr,o 7+n t9)qkn2hq vegpq. j.uuom the horizontal position shown. In the absence of air resistance and friction, the mass swings through the arc of a circn2e +uh kqpg.v9qn ,.) 7jtquole. 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 forms a simple pendrl sp9 zqdbdu+p2j uhf*(vve,5w0:+xulum. 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) whenvl9*2z ud5:dh++purb( evjp,xswq 0f the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stoppex :sxoh)mh)1: dhf 2fbqh( -jer 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 speed v, and the frequench hm:)d2f1qf(xehhs)b j:o- xy f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an ideal hond26oc r13f2p3 rtvoy hl66njrizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds it at thi13n rd 3fth6pv c2jrlyo62o6ns 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 in a ver4axadak2;:6 n nr- ceotically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowesxa2ack; n 46d nae:o-rt point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontbm jfb-3jix2)hp; t ,yal 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 y-, 3jhxjb i);pbtfm 2from 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 about94tpr8dona 8 x 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 forms an angl 4p 9xroa88tdne of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform circular motio7t; d- s:.jyn1zxkbcqux(d 0 in as shown in the figure. The string to which the mass is attnxzciu ysj0dk 1:7qdt( .;-b xached 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 3qxh t+zo,t(nb:hh5+b 0.0 cm from a horizontal disk’s center. The disk starts to rhhh:qz(ntt xbo , +b5+otate from rest 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 kgx( jwue hbt)x.2e y4k0go0lb6 is attached a distance R =1.75 m from the fixed center of a disk as sh46gjwhke x)o20yb0 ( xlu .tbeown 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 cdjnm + -mwa5- 4uwrff4ircle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly un u ja+ -4mfrnw4fdmw5-til 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 8jin(-eet,wa k ;w6/l9tzd(/yo yzgyspeed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle o twnz kd8yy/gt(iw-al9 ;/, ze (eyoj6f$55^{\circ}$. 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 t5nrlt p.6 prx+he bottom of a bucket. The bucket is spun in a vertical circle of radiut+ .r 5p6lpnrxs 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 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.