95.02: An object shown in the accompanying figurij, 1azn q0 b+wl2n2/ xq2xcwre moves in uniform circular motion. Which arrow beqb rl22j,0 i+1xz/c an wx2nwqst depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclzd(-d9 *llm dbockwise at constant speed at an amusement park. At tm( lbl9 -d*zddhe 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 circular path atym: yj8v7vtm+ix k4j2 constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from po m: y42mvvx+ky8i 7jtjint 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 wnima+5a foyo0 )kmof5 jp550 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. Point Q is exactly half-way around the y+m55nfw om)af 55kijpa 0 oo0circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constant speed ar i ynlj;c5ppr9 7y*rc(ound the vertical circle shown. Which arrow best indicates the direction of the object’s instantaneiy ply*;r95(cjn p7rcous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to(,i7tn :te gmmx- 0+dcdspr c-o4bve* the end of a string counterclockwise in a horizontal cid:b eg -t,smnx+cd0 v(p4-tm7o*rceircle 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 should she let go of the string?

  15.23: A car moves wituw 1w(r .df-nph constant speed around a horseshoe-shaped path as shown with the arrows in the figure. (dw-wf u1 .rnp 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 experive) -m 9cm/kcp7ucg g.wjg+0b4 kock5 ment with a simple pendulum that is .wbc7kue k jggm)kc4 /-+ 0 o59pvmccgreleased 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) pg ta+b /wo)ygic0jwm., z-s0h oint-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The period of tb.- wcgjs)0/+zwa0thoim gy, he 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 keep1r32 ftpyhh,ybh)qh0 a 1. 0 kg puck moving in a circle of radius hfy )0bt3y,2hpq h1hr0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accelerat 8 ovdp8,lwpn3ion of an object (mass = 50 g) on the end of an 80-cm string pd 8 vlp3,w8onrotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular patav:.sm j+5 bqlh of radius 0.8m with a constant kinetic energy of 128J. What .jmv:bl+a sq5 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 0.5ent5.coc4dgh ss21 r q-; aln80 m string and whirled in a horizontal circle a5q5s r ldt1on n.4hcgec;2a -st a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in ah8caxd0,do h .2)0csbfp uqj+)foi)j uniform circular motion. Which of0+2 ua )fhscoxp)fi )8dc, obd0 qh.jj the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attac,piqgt 5azq 8-hes a mass m to a string 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, radiuspi-8aq5z,g tq , 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 whi x6hxt5(g1zrr;pr- cdch it is attached makes a 90- degree angle with the vertical. The mass is relea 1-cd ;rpz r(6r5xgthxsed 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 terrain, see figure to the rig )5iro:sy:7ik+p x vy5g2f yrcht. 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 feel weightle7is5k ::f xc2+ yrvg yi5royp)ss:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/4 a/)n6 9z ee9juilfgjs. 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 figurenujez9/4af6 9 gi j)le. 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 conny4l3 aldhsbe. m.-ql;7 bcg9stant speed. The magnitude oq3ll7 ysebn- c9 hbg.dl; a4.mf the net force on the sphere

  11.47: A simple pendulum of lengcssiq tf(mf2 3+l)ni0bve+, ith 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 magnitude of the force from the string on the mass (tension), G represent the magnitude of the gravitational force e0iivifl+,mn 3c sbs()qft+2 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 p ps 1 1:pbsarrd*y*gz wuva,2 w-)uh2mendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the 22d bzpgwh*p:*)1 asmws ,u-varur1 yfollowing 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 5.0 newtons is applied to a rubber sv xw( b b1.:tsbm3rha0topper moving at a constant speed in a horizontal circle. If thxb 3wtb:h a10r(b.vsme 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 frictionlessm8a yy jf/4jj7 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. The 7/ajym 84 yjjfspring 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 4.4 bd rws (xn pb+jxb:95vl :kusr/:we10 kg mass 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 t:jvrwl1 rdb ssw:/ xuke(bx:n9p 54b+he mass when it is at the lowest point of the circle?

  14.23:Two small identical coins ( s3l b+ulvb06/pk-f,/im dhyzlabeled 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//klfl6sud+,v 03 mb-b hyzi p 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 cotr) j1/uu+fpe nnected to the end of string and moves about the string’s fixed end infup1 t)+r/ue j 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 circular motion as shown in the 1y ndss h5-i/s 4vr+icfigure. The string to whi -4cr snsd yhis1+vi/5ch 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 a horig9hh: r/xbav( zontal disk’s center. The disk starts to rotate from rehr b:(9hxvag/st 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 massu jut 60o9fhyi/g0 tuj jdo0:+ M = 2.0 kg 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 resyg6fjj0h do ujto00 :uti /+u9t 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, sts r )fs,andwnt)tly2+7 jx5vc,0 a0ywarting at the top, with initial speed 17.0 m/s. The object’s speed increasydrtnsya x at)s0cj w 25f,+nvlw,)70 es 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 speed 1b r4p(.vehy (c7.0 m/s. The object’s speed increases uniformly until iv4y(br. p (echt 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 thpaq 1x damtj28).j kc.e bottom of a bucket. The bucket is spun in a vertical circle of radius L by a ro jxkd8.maq j.2p1)t cape. 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.