95.02: An object shown in the ac8 xdvb.t: fcp dscnk11pc-bd*6l t+oc. h8+udcompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the ob8p+dc*c-sbn+t6c8 1 1c.kdxvhddlbo u ptf: .ject at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotmrm sj:g 2n 0xa +g90f *mlbj2mn.m*olates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat and m. gal*0+j0j2 *mrmo mmnl2 9nxfg:bsbelt?

  08.14: A particle continuously moves in agi0ub,uo *wh9b.x(td circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from poih o.bx wg0, tdb9*uu(int 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 con7 --tpyzc5/ a/z /oionyst,mg42ag;rpqc. ju tinuously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interv 2;oj s qpz4g5 cy/i.,m7nc-uor/t p/zta- yagal 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed around the vertical ci6a 4u(k+wq54k; ztqn qhgrz v5rcle shown. Which arrow best indicates the direction of the objecgvqn arq 4q56+5 ;khz uz4ktw(t’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected /)x c9u:e nhbk5b h5.r/:qj1ynnf oji to the end of a string counterclockwise in a horizontal cjon n 5b.e qnux:ky):r5cj1f/9 hhbi /ircle 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 with constant speed around a hor5auc-8 h -a.bmmftpn8 seshoe-shaped path as shown with the arrows in the figure. Which one of the following choices bman88 afuh5c- .m-pt 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 that h+(vzasy3u p+5wje3i is released from the horizont3szj 5a+v+h3 ywie p(ual 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) point-like object rhv 15rsdt0p 1wests 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 turntable is 0.50, while the coef hdptv1r1 0s5wficient 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. 0 kg puck moving in a circlek 65069 v1l xxws*bk apqbiih1 of radius 0.5 m on a hos6ap qh l 6k*x19kv 5ib01ixbwrizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripe-/iy xs v v6-q;qqkph:- ol(sctal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of/qsqh:-v q ;6(p-iy o-klcxvs 4 times a second?

  09.24: A point mass moves along a horizontad( kj2gi:suh( l circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net fo(ud2 khjs:(girce 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 h*mpb mo;c(tf1 orizontal circle at a constant speed ofbcm (po;t* 1fm 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 a uniform circ yh-h 4e t5fjc)1*roxsb7 0assular motion. Which of the following statements is NOT tc5rs1 xoj e)0abs f*7 -sth4yhrue?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a strinlq.hl9op nnkxmkd2:*9 qb p4-g 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,bkn.l l9mh 2-px* qpoq:nkd49 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 stringanb(q( rcg 4 ghfs*x/0 of length L to which it is attached makes a 90- degree angle with the vertq (f gb/0c*x 4nrsa(hgical. 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 terrainv i22cga2-cqg, see figure to the right. 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 weightl-aq2v2 c icgg2ess:

  17.10: A 2000 kg car moves over a hill apttqhaxby(7gs(8 dq5cl(;rf j 7z ; q/t 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 magnitude of the upward force exerted by the road on the car? (htgldb;/qjr x 7c8 ;ytf7pzq (q(5as

  97.13: A small sphere is moving in a vertical jj,mp ggtqgw.29/ *ibcircle at constant speed. The magnitude of the net fg9pbgj jw2.t* ,iqg/morce on the sphere

  11.47: A simple pendulum of length Lhasa (u+6yecns 4jf,:q royg3n5 sppoint 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 acting on the mass by the earth, and F represent : yoeryfpu36cnqn s( +jgs45 , 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 connec( jc*g4 ) ur,aiwitd7lted to a string forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the ji c)7(i*u, rdglwa4t 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 newtx+d*w0 0woexgons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smal o0d xwe0x+w*gler, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on ro y :pj)*4o1nrcwjty r/ .dm/s u6j9ia frictionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds it atjyurn: y/o9*.6/4r1icdmps jrwj )ot 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 maf)pp9 a) ye-)m5 sltfk n+t;uass 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 the mass when usnt)ea kt5pf ;yfm- +9 la)p)it is at the lowest point of the circle?

  14.23:Two small identical coins ( 0lx (mccq (z t--ze)cel;qjb/labeled 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 cente q- czmqej;/zc el0 (cl(-)tbxr 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 moxfexaln3.f8 4 ves about 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 anglefe3xl8x f .n4a of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in y4nvt8f-u35jng7f ixt2t v d) uniform circular motion as shown in the figure. The string to which the mass is attached has a length ofx7)n vyitn jd-ft84uf 25tgv3 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 301 /ne05e*cg p 81wwifu( roqlu.0 cm from a horizontal disk’s center. Tu8wfoq*nwi0151e l cup re(/ ghe 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 = 2.0 kg is attached a distance R =1.6nk-0gpf iy7c 75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from re -n 6f0cpy7kgist 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 the top, with imp5 w)qrch:; initial speed 17.0 m/s. The object’s speed ih mi5w; rq:p)cncreases 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, /y i).hvu9:8zlqz em/* o iw8a d:wskjwith initial speed 17.0 m/s. /mzsjva oiz e)8:uwiy.q8 : w*d/h9 klThe object’s speed 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 time for this motion?

  17.38: A small 2.0 kg block rests at the bottom of a buck5 s55:ipsn)lnig-q6 b; fc.wxqy 2wciet. The 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 bucket. When the wfnq yspg;5cws:5.i)x - ic65i2qn blbucket 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.