95.02: An object shown in the accompanying figure moves in ufbza xq6c c i5 9,h*io*x:wvn7niform circular motion. Which arrnz6xh,wi iao q9c c75f*vxb*:ow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotatce r/(i (nz0aqes counterclockwise at constant speed at an amusement park. At the location shown, whi( nz q(ciaer/0ch direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle c j5)6b dqfg2pgr.u /raontinuously moves 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 gfq./r5gj6dur) 2pa b 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 sqz2nl xcp+)9 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 circle frompl ns9q +2)cxz 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 verticaqxc0)o k d-lu/l circle shown. Which arro/0cuklq-)dox w 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 the end of a string countercl x2./kd nrive0hy ;eu/ockwise 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 of the s ieenv2 .k0h /x/yrd;utring?

  15.23: A car moves with constant6x /u 0g4hvcig speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleratxg4c06gu iv/ hion of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum th vvs;d7cnzdy,,0 c-ag6efur 8h(qjf6at is released from c,7c6- (r , v06gf;8ayvhje dn duzqfsthe 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) pointfhhqhm53 .3ygr/o/n 3zf8-hsaje x0x -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 turntable is 0.50, while the coefficient of static friction is 0.80. What is the 0a83 hh3.egmj yhf5/qfnhx -zr 3s/oxmagnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puc5 xj*d(r5ruwe +zs r9kk moving in a circle of radius 0.5 m on a horizontr+ rzswur 5kd xe5(*j9al frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of .dabi*(wg() qv c8 dzyan object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate c(q.gbd*wi(8vy zda) of 4 times a second?

  09.24: A point mass moves along a horizontal circular path c,uyh -aplp 7if1 s73bof radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the pays,f-luc1 3hi 7bp7 mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirle+(tpglo)jctgwl ( 4g+d in a horizontal circle atp ocg) ll+ttwj(g 4+g( 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 a uniform circular 08) ervdvwq5m tw2anr;87w0mst 7 0iv+ wkwxjmotion. Which of the following s n)twxd80wa 5 7i;jr 8emv0 2wwkvq7vs+rtmw0tatements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches 2a7f wp va,1iqa mass m to a string and whirls it arow2ipq,a1af7v und 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 pulled outward until the string of length L to which it i 9kro6 eko5 l9bts(e9gty*;wqs 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 thk * tq5(se9l96roy;9eotgk bwe mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a qaxv+ +n1j+ :4uleq yo etdc36road in hilly terrain, see figure to the right. Assume the car has speed v and the tops a 1:+3+v+do46 yclnq qae ujextnd 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 of 12.0 m/s. At truiv593wu7g ath4 j, whe 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? ju,g aiu rtw54h397v w

  97.13: A small sphere is moving in a ver4gyo+ /d il1u z-et eq15hqtc.tical circle at constant speed. The magnitude of the net force onyqoq + 1-z1ti 4/e dlug.h5tec the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest/p xj*(sfw ;x /iby.6nhep-w-dn5 sxu 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 the magnitude of the net force acting on the mass. Which one of the following choices de/x njp6f-5i hsb. snpxd xy;(ww-u/* escribes the relationship among these forces when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connec4lfg: :a:k6-y:k 5 on ur8ci4bptweq qted to a string forms a simple pendulum. The mass is released 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 gravitatie:qu: kk4g 4i bo:tcwpqlyr: a86-5nfonal 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 for /0jwy+w7cr eucs 9pa3.u.judce of 5.0 newtons 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 smaller, what happe ucue r0/s79..w djjupwa+3cyns to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at resz a4w)vq9pgiu, 0b xy*8nmav 2,r1 pddt on a frictionless surface, connected to an ideal horizontal spring that is upstretched. A pe2b) 94 8, *da 1 dqzpvwripva0guy,xnmrson 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 there?

  12.22: A girl swings a 4.0 kg mass with a co) f d 1bnk5;ijodmg:va3u0ay 2nstant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net forceuaid3fjky:1o);avdg2 0n5bm 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 vk6 sgkaeh2 21am: mz5disk rotating at a constant rate about an axis perpendicu6mm:s2kza 1kh 5vg2aelar 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 rm) *sw dj 5xyi(xx(8yis connected to the end of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. Try8 (m x(5yw x*dxs)jihe 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 motgeqi kc761t1yrf*3olix50v e dl k4r9ion as shown in the figure. The string to which the mass is attach 7i e3461kq9x5clfyer id*l1trv0 goked 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 11.0gdof)oe8dh:2u 3t h .oe is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its cen8uhd h:ot fe32ood).eter 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 p02zm q38 nngu,na1k uis 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 const8pnqg0n muak1n 2,3 uzant 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 th36tas6(i(q0teqlkb j e top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclocs ei tlq(ja3(q 6tb60kkwise 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, w7qcg(haso d po+mg967ith initial speed 17.0 m/s. The object’s speed incr g9adho+s 77oq(pgc6 meases 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 bucket. The bucket ish ;f;f,t j/sdu3o/x eo spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just/ x,;;3uooftesh dj/ f 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.