95.02: An object shown in the accompanying figure moves in uni44 rkm r5/f:k3l zaq,nwv j1etform circular motion. Which arrow best depicts the nea:l kr4zt rmv5e1jw qk43f /,nt force acting on the object at the instant shown?

  05.31: A child is belteb (djolk 5j5t/2ka l2id into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amjjil2( d55kat2olb/k usement 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 continuousqp(1 :6uaf, o/fyc2 /tguvq dily moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this c:p difg1vuqc62t a/ouy/ ,(fqircular 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 conlhk hknpcc37np(; hy 4buuj+ 4:a1t j0tinuously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval dur 3j47c1nhu(;+cahu4 l0jpbt ykhkp:n ing 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 acceleration during this time interval?

  15.07: An object moves clockwise with constante,ud ,cj.cieew2(li.vxs/6 m speed around the vertical circle shown. Which arrow best indiclwejusvd.,e m(i2.x/ 6c ie ,cates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a tca bs-m)f m(uo /7;pwsmall mass connected to the end of a 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 lettered7-op )tfsabm (wm; cu/ point on the path should she let go of the string?

  15.23: A car moves with constant speed ara-sj7gw0;fgtnq x ;pgr/+yy: ound a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the at+0; ga- r/ qs;pfwn:yggx7jyverage acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a sain8tg yy*dkv1j3;n()q t z 3.zx xr;aimple pendulum that is released from the horizontal position at rest. At the moment shown in the diag n1v;xax;y n ztzid8kgr3*(3.j ta)q yram 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 kge. vyt.ve +x:y ss++tt) point-like 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 friction between the object and turnta.t+x.t: ve+tsevs+y y ble 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 k5akf1bt5gnu-h 5nd:3e afbf2 eep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.uf5-kbb daaeg5f 15:t 3n 2nfh0 m/s?

  05.03: What is the centripetal acceleration of an object 1zw/t * spudmj9,ns g ud.*;pj(mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a secon1 ms**nzjgtwdjpdu,/s9 . p u;d?

  09.24: A point mass moves along a horizontal circuddp.fxvo aj 5o09xrzlin p- aym6yg,d31721rlar path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net forcn0-9 oo7d 6i apfdxrp1l .yxrv 2 zajd,3y1g5me acting on the mass as it moves?

  96.24: A 2.0-kg ball z: 80zk5 ng vieqzd0: c;qus4vis 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 the ball during each r; 0c0gqzzv::d4n zuki85qe v sevolution is:

  99.22: A child whirls a ball at the end of a rope, in adz42 ,nl2f ad r7ggb5q/yjz j )1jjsr/ uniform circular motion. Which of the following statements is NOT truejgdd,sj)bj/ arzrnl/q zf 1g452 72yj?

  00.19: An astronaut in an orbiting spacd6p8j*l;;oq( qg xi rce craft attaches 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 ri(p8 qqd;oxj;6 g*clthe 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 pullevluc a(sg(, , 5mot hw:wvt;1ed 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 through a circular arc. What is the tension in the string when the mass swings through the bottom ofu svc o,agtw:vw1m 5(,(t;e lhthe arc?

  94.15: A car is traveling on a road in hilly terrajdqr 2*wu ab4il*jszkm/,c4,in, see figure to the right. Assume the car haszl* ,j*4 /,dkrjqm 2cabs4iuw 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 weightless:

  17.10: A 2000 kg car moves over a hill at a consoiin6).3 d 71zxsnzflc gj6y 5tant 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 o7y)5lnizd63j6s iz c ogn1.xf ne 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 cod0pq60fz iyaf//my24q u+idb nstant speed. The magnitud /q4muf6 yb2d /0iz+fy 0aipdqe of the net force on the sphere

  11.47: A simple pendulum of length Lhasa poin4c7 z hs,pg*6 sf5entlt mass M released from rest from the horizontal position shown. In the absen,tsfpczg h6sn*l4 7e5ce 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 forms a simple pendulum. The mass is rt(yl;wk+d )hk eleased 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 mass swings thkkdw)(thl +y;rough its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper moving o3vh mq)a58 cwj2ih2f62d qbf at a constant speed in a horizontal circle)aohwidmj2v23 f bh qf562q8c. If the 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 frictionless surface, connected tabang,yg +t7/j1t5chpezwu 3o -q1 ,do 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 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 t-,jp bd tgywa1e5 z1g qhn+to7uc3/a,here?

  12.22: A girl swings a 4.0 kg mae ofmc3uh m2o3ec cp)vf9*9 4zss with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75eme 3f9mco p4voc*u9hc23 fz) m. What is the net force 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 reston a horizontal vz*hm90t2amt;k f .8x y tm:ehdisk rotating at a constant rate about 2:0xmv f*.t;h9azhmkyett m8 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 thh8ml26z rxum 4kb5f,he string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The 25lbu4mk,6h rmzf xh8 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 mu95t x- p(tmq .snmr,in uniform circular motion as shown in the figure. The string to w(mtps9 m, 5x ntr.u-qmhich 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 k1kz- xm y;a0p.vc(,wioz si130.0 cm from a horizontal disk’s okiz0 sky1 z1v.ai(x,c; m-wpcenter. The disk starts to rotate 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 massmhs kkk4 c/dc8ho4ahx,-1s y 5 M = 2.0 kg is attached a distance R =1.75 m from xkhd5h/s k8 4sa-ok m,h4c1 cythe fixed center 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 y ai,f h*svg x18ea11/ yka f(*.mrvad6bz)uh in a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throug1 8m /vz f hfih **1ebv,6) 1dsyruaayga.xak(h 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 17d v5w*1 v6pntd8 gjqs7.0 m/s. The object’s speed increases uniformly until it has movgtdwv7 1dn8 p5v6qjs* ed 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 bottom of a bucket. The buckej. xltuubw a 9cp 0t e67wzt17++tucf2t is spun in a vertical circle of radius L by a rope. When thefw91btt+6cu7 +tt czl xpuwujae .072 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.