95.02: An object shown in the accompanying figure moves in uniform cbk 1,w (4ej nxla 9vlegs85n2lircular motion. Which arrow best depicts the net fon8l5 xl9ak2e4 lwe1jvn (s,gbrce acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheew gqoy.*;8qe eyou5 e29;a) +vudu bfal seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total f +uw bg9e;dovuq8;o*q.2yua)fye ea5orce exerted on the child by the seat and belt?

  08.14: A particle continuously mox *drmf-1ll(+ )g- c(cv(eopsrn)y t lves 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 circt)-+(-fpx ndevlcl s ol*y1(c(grr m)le 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 const azhj n5u1s70mant 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 hamu1 hj570 nszalf-way around the circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwisem c9; zj9yjc-v(*: vh2t 1fye-skzxrn with constant speed around the vertical circle shown. Whi-9 k( er*c :21-zvsyn;fjcxvtyhz m9jch arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to ,fqra( iigh( +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 lettered point on the path should she let go o,fiqg (r(+aih f the string?

  15.23: A car moves with constant speed around a horseshoe-shape kua-3fw 6uceq o456nfg h,k7od path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling fkh6nc-q 3eoau7 o ,f5u fgw46krom Wto X?

  08.35: Astronauts on the Moon perform an experiment wit9n-sp c be r+5jbvyx2(h a simple pendulum that is released from the horizontal position at rest. At the ms2 pc9r-v e 5bnx(+ybjoment 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 rests 2.0m from tvhi*+t9)p:s4on r amu he 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 coefficient of static friction is 0.vt+ io4pm9hsr) un*a: 80. What is the magnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep ap j kq+a:9: toi8s/p :2zeqevn 1. 0 kg puck moving in a circle of ve:aqsi:znt e+p2j p: / qk9o8radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetalc*d eajpup/w al x* a/18u6*5jz x2xxe acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant ratexpp5 /12*w* dul*j u ca/eea6xja8xzx of 4 times a second?

  09.24: A point mass moves along a horizontal circular pathoruo2oh -dv--wcta9mxu0n( - of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on t (-armnuv2-wo90hu oxotd-c- he mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m 3ftm4nt rqet b 5sy ,11fg*mn.string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the rif1gr4stmnbq31yt n.e *,5fmt ght. 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 ccxnx )ezt ;q0-ircular motion. Which of)-zntq0x ;exc the following statements is NOT true?

  00.19: An astronaut in an orbitin1znxaj:5leckh ;(,m pl0j bc)g space craft attaches a mass m to a string and wh(axj l0)m5ncp;lej,h: 1 ck zbirls 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 maintain uniform circular motion would be

  07.22: A mass m is pullergfvxi/q0 *k:vpk: 9ld 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 tf*09q/v vp :kkl :xgirhe 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 fig7dws fpt n+d)/ure to the right. Assspf)dtw7dn +/ ume 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 weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed e cxndm8qd5e.t ys3+99gf3s it7lju; 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 r;q3m5si8g x7d3euf c y.d e9+ njt9lstoad on the car?

  97.13: A small sphere is moving in a v33q wxnxhf)x66it+ wh ertical circle at constant speed. The magnitude of the net force on the spherewxh6i63)ntfh3wq+xx

  11.47: A simple pendulum of length Lhasa poiv6qs,1 c ja+f ow9z-tent 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 oe6z v+s 1fjtwc9q-,aon 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 r.f9rv u1 dq fcnwe)57tz(d /smvi,m h9eleased from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranktvd 9mh7,weudif/ f .s)qr5(z m19vncs 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 nn3o l3f 0ifjvh:rf; k9i7ta8 a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radiusr93;ljo3kvtiiah f 70n:8f fn 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 fr jan2otg5t85s+ ysd pk.zxi6z:/d(l jictionless 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 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 sttj:xz68il d( / 5. nyks5djts o+2gpzaationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 3.24et1veb 2,rc c28ms5r (ba,pdb m/s in a vertically-oriented circle of radius 0.75 m. What is the net force actin1atsrbr52,8 ,dvcmbeb 2c(e pg on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) 4sb4mr/mi0emy kk20 m4. aw faare at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and thmme/ 4krym04f w4 a2ab.km 0isrough 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 jv5o3gzcyhsj3)aau7tn5e25xc + vn7moves about the string’s fi cvhjn75 szot53cu3x7+jav a)y52egnxed 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 angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform circu4-i igbg/r zqz(x0*nplar motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an anglen/g0 b4ig(qxz-pzr* i 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 fromaa: r+w d 4yeic6l5l6m a horizontal disk’s center. The disk starts to rotate from recea66: ia+r5wdl y4m lst 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 withp0xbxytig-*tn/l**xwn ; hr:g 4s*zb xoc)1h mass 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 rest *h: b -lyx;s4ix1hxt) n tgocgz0 n**wrp/ xb*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 initial speef 3p/:nvg4san d 17.0 m/s. The object’s speed increases uniformly until it has moved countercn/p3fga: s 4vnlockwise 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 lj/mciz+*(;vx/jx a vhn;+uv at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly untilv;;/a(m*l ivj+j /hx zux+ncv 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 bx ,q wqbbi7 .w- l292,gjwjhac3o kh izj.5,zbucket. 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 remainoj.xl h w9c.jihw, b wq2,k7zji ,zba532 -bgq 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.