95.02: An object shown in the accom zzk/8r4xs/ aotww285te (a sr7bx7o fpanying figure moves in uniform circular motion. Which arrow best depicts the net force acting rbt4r/e zt kw(2f7z/ x5a x8sa7ws8ooon the object at the instant shown?

  05.31: A child is belted intoj+eaz*o2q/ wa(:yar1j1( d6xs nn f yl a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which directx(11*yde (6 r+f/a qn:wj j2 oalnsayzion best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circulta xwqui46r5s,cgn 1 7ar path at constant speed in a counterq,w6 rusc xn1 i5ta74g- 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 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 speyw w(gmxrs-g9w l/8* red in a counter- clockwise direction. Consider a time interval during which the particle moves along this circyw-8 s/gr9wr*(wxg lmular 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 arouhzob3jew +0ue6b9h x5 nd the vertical circle shown. Which arrow best indicates the direction of the obe3whu he6 b0obxz9+j5 ject’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of aa3jdp/t6/fd ,f5rvl m h*)kzh3m9lxa 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 point on the path shoulljm 6a3p) d,fh39x 5rdhz/* fvm/laktd she let go of the string?

  15.23: A car moves with con6jn 4+1 iee (qbqaykf*stant speed around a horseshoe-shaped path as shown with the arrows in thqbny*qj6 1(a+ kifee4e figure. 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 pendulum t+5:ta u2nu gvchat is released from the horizontal position at rest. At the moment shown i+5 nvtcu:g2au n 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) poh9snst54 v5oap yvb 36int-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable'5t3 6hsy49v5bo pnas vs 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.. z9: pe6fu c8iqz ul*.9sacja 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2. ezjasc9 :q6f*lz8.9cu.paui0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50faz cu7(a k-3ih3+ hx1r ws-ur/bjz2oj5e r-q g) on the end of an 80-cm string rotating at a co3 c-jrrxk(5us+ij fw--/7 bq 2ozazeuh1ah3rnstant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of rad*yhlyc0y8fus h6lpa9 1 mdu.i+)d na.ius 0.8m with a constant kinetic energy of 128J. What is the magnitude da*lhnpumy. d6l1 i +suf yac.)8h09y 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 in a horizor wor 9kz0f e)a.c,cog5:c*upntal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on thw*pc, o9rrea:cg 5f0 ). zckoue ball during each revolution is:

  99.22: A child whirls a ball at g;gzq+v meun5i+o 69lthe end of a rope, in a uniform circular motion. Which of the following sloig+vm;n5z6 qg+ eu9tatements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a stria f zl++d2l2x by6ds h0y7r/mfng 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 the tension requb27a 0/lf2dh6m +rls+ yxdzf yired to maintain uniform circular motion would be

  07.22: A mass m is pul:3in bkw4f6a.ahi -rv *g:yzaled outward until the 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 throughi3:z:* -nhbyia4 a.rk a wvf6g 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 terrain, se u.b*b/ jz vs7apxd7vx1 8s5aee figure to the right. Assume the car has speed v and the tops and bottoms of the hills have e px8xb z5dsbsjav1*va /7u. 7radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.7 2c+9yliqlrlv0 ppg.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 representsrpc vp lq70.li9g+2ly the magnitude of the upward force exerted by the road on the car?

  97.13: A small spher)/ f;mt5kewltm 0ylpr)nu*f7e is moving in a vertical circle at constant speed. The magnitudellkeft*ryf7) mu p5/;w0 mt)n of the net force on the sphere

  11.47: A simple pendulum of length Lhasa poin e .j )qnby8yb)rl7ut9t mass M released from rest from the horizontal position shown. In the absence of air resistaybrj9)lbe7nqt)u 8 . ynce 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 ol 6nvb/:vgqdz1 bw/: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 bq:/z:vd wnl1ov /6bgthe 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 5.0 newtons is applied to a rubber stopper m+a0bodeokuyi : g 1o,;o 1v ln5iw.wa)oving at a constant speed in a horizontal circle. If the same force is applied, .1gwoud i+v;oila e: 5 w0 yok)1b,onabut 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 o-yl b.jj s(ph)n a frictionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm frob.) s(-jypjhl m 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 r 2 qim.mqngj 3;i;*u naaz(e7m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on theqmnmia;3 (r ju*q ine2g.;7 az mass when it is at the lowest point of the circle?

  14.23:Two small identical coi*ao a6+leaw1a ns (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plana+eow*al1 a6 ae 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 the r,ae1g9z igx4m-a + vfstring’s fixed end in a conical motion with a constant speed of 4.0 m/s. Thaz xgrm4ifeg a, +-19ve 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 circular motion as shown in the figure. Th;i21*ch w j.bbl7uyfscb 7d6wp1 qi; oe sl*721fc .w ibi obbsh;wcq7p;6uyjd1tring to which the mass is attached 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 30.0 cm from az rxg* .xvm2 qts)/t.n horizontal disk’s center. The disk starts to rotate from rest abqgr.tsz)m.v */n2tx xout 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 k +f)mxn3-7tpp,0 u uusd:opmis attached a distance R =1.75 m from the fixed center of a disk a x puun7om,uppm+ts0: )f-k3 ds 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 thezvc9d cem8)rqa5c 4 f s5-(eji top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countercl()9 vij4z85c -q sda5refecc mockwise 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, s 91 p6rhs rzrl53/mcvwgjz+g6tarting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwisemr+ 3rrzhl169g wc6j5s/vpz g 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 n.b:aho) 2nbr 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 buckeborbn :h)n2 a.t. 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.