95.02: An object shown in the accompanying figure moves in uniform circular motia6k hjt)hwc;1 by /6q z.g)afqon. Which arrow best depicts the net force acting on the objqbk)t)aqch a1j/6 f ywzg;6. hect at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclocac5t +q 0sm7rakwise at constant speed at an amusemen mt 0sra+5ca7qt 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 a circular qt4pb(i:sv:gnv sv ),path at constant speed in a counter- clockwise direction. Consider a time interval during whicvn:gi (ssb: ,pqtv4 v)h 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 spe w hpl-k2do352( tmuyqed in a counter- clockwise direction. Consider a time interval during which th3pmd5q(lu2o - khty2we 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 the ver ).;x p0.bnqfat /.(tmt tgtbwtical circle shown. Which arrow best indicates the direca .bmtt.xb 0n(qpt;/wfg.t)t tion 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 so g+. mh 1d u3(*yzrvv9w;ze 2+po5ubd*ccavftring 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 sh5vd r+p1 oy fu;v23aeo9 .mw+*cvzub (cd*hzgould she let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped dl4vv-s 8a+ iwpath as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of ths 8v-wa4i +ldve car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with njkvdhj/*i,7 a simple pendulum that is released from the horizontal position at rest. At the moment shown in th, *i/j7knvdjhe 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 rests 2.qwr3)d(jrv, l0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation3dlr()j rqw ,v 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 kee5r u50mi0re-kbbi cq6p a 1. 0 kg puck moving in a circle of radius 0k5i br-qb 0r0 c5mie6u.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mzkt za-d aqjj5v69:aaj04n; iass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a seconv9jz6ja d5i4:0; jnq a -zaatkd?

  09.24: A point mass moves along a h2r bi( t6aayp/x1nae; orizontal circular path of radius 0.8m with a constaa6y r2( naeix;at1 p/bnt kinetic energy 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 attached to a wj z qk4zgm9 m5:c 25hnoh(j.xsnm-(z0.80 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 revolution is: -5nhco xw zksz.(jnz mm2j(mh49q g:5

  99.22: A child whirls a ball at the end of a rope, in a uniform circular motion7gyp8 *gn-e lpf, rpa;. Which8p- ;fray,7leggp* pn of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft *ojy*v 95x8dw/fkh ra 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 the tension in the string is F. If the mass, radius, and speed were all to double the tension required to mainf8 k**vw 5djy /rx9oahtain uniform circular motion would be

  07.22: A mass m is pulled outward until the string/// t)jw :mkmgu ;x9mzytvs3 l 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 te3w/ym 9v: kjxusmtt/;)l g zm/nsion in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling6a+wpy9,cdlj*df;mq rzc :31zs 7 dtx on a road in hilly terrain, see figure to the right. Assume :z x+qd az 7sml*w9djt;p 6,cfcy3dr1the 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 weightless:

  17.10: A 2000 kg car moves over a su kodw,3x d *gnez0y-yd 4nf39x19idhill at a constant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be approxima903egzyd*, onddx 9 xk -4n yfu1disw3ted 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 on the car?

  97.13: A small sphere is moving in a vertical circle at constant speed. T0fhs 0hs.vuf) he magnitude of the 0fhvsshu0.f) net force on the sphere

  11.47: A simple pendul6e7 z/u: 0 0filuyzcoeum of length Lhasa point mass M released from rest from the horizontal positioncle:u/oy 6zi 7z0 0ufe 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 when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simple pendul(vbz d6 ph; ,+nfaigl1um. The mass is released from rest and undergoes simple harmon(z+,; fnv dl1abp6h igic 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 through its lowest point?

  04.41: A centripetal force of 5.0 newtons is apfd8b,a vtsgd/ 6g/dv, x7hbn*plied to a rubber 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 speed v, and the f 8hdgn gvbd/x,vb7/ ,fat*s6drequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, c.ji.2ms .k tqi0w ks(yonnected 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 spring is brought back to equilibrium and the mass connected to it is now doubled to 2M. If the ss.q.ws 02y(j ikmikt. pring 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 ver (;,hs8psx-pim2nfwk tically-orienwsip8pm-x ;,skhf2( nted circle of radius 0.75 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 (/*txb9: z wsun.3wer mlabeled 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 center. The distance of the coins from the center of disk is re b:sz3 xuenw.9/mw *rtlated 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 moo41im-qsfm.thwy qq e 8s1 *503aag zoves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The striz 0yq otf1 saq*83iq14wsae ho.mg5-mng 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 circula*qbj)v;i dvg2c;be1 j r motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 vqbd)*c bj2i j;1 ve;gm 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 ro-zj ju-)dcs1sm /2w rest 30.0 cm from a horizontal disk’s cenosu z /1mw-srdcjj)2-ter. 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 mass M = 2.** fxl7dzm/-pmf efu90 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 rest with constant angular acce m*f m/pl x9ffeduz-*7leration $α =5.00 rad/s^{2}$ 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, startinq2d, gr zsx+v/g at the top, with initial speed 17.0 m/s. The object’s speed/rgz+d2s , vxq 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 circl 9z s7fi:2b dj;-4 mi.afb y8qkzdgpc6e, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle . 8bg f ;m6s:cz9ad 7bdpy4zfi-2kqijof$55^{\circ}$. 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 bucket is spuiti- pd)yao ;q,uo t9;n 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 buoqyat;d- p ,u9;i)o ticket. 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.