95.02: An object shown in the accompanying figure moves in uniform circular +0 oh+ wv)kdkga8w*2(na9aew + dpvzwmotion. Which arrow best depictsn 8evk9a+ ahw0d+odz*w)gw k+pwa(v2 the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seatl6f,qjay 0q hq*b; 8yc that rotates counterclockwise at constant speed at an amusement park. q6yq *, ;8cbhylaq fj0At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously m7g4 7 kryloqa43-rx 3xkt7obk oves 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 Pg73 4rx3o7y7 r bkx-ktok4qal 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 circsr2n u m5 ,k)ng6mq.u :3ddjuai*ewc4ular path at constant speed in a counter- clockwise direction. Consider a time interval i.knj42c:wqunm)g6usuam rdd ,e35 *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 th2 he qh-w/d t2eai3o1le vertical circle shown. Which arrow best1/ leiwat3-2o2hdq eh 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 endq xldzan4al)gs1 / 1)rm;i*ez of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’sn41dg)ie *s/ xzz1ra)q a lml; 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 cva*j-ee 8mo6+t lzo k2onstant 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 acceleration of the car in trave*-oo+jteae28l 6vkzmling from Wto X?

  08.35: Astronauts on the Moonivk44a v(cl5k *vf:a:- jf cpd perform an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in th-aj: kpvi:f5a(*vcd4 vcf lk4e 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 frompgyfw ;nl+(*y j q:p*j 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 coeffn yp: j;y+jlw qf(*p*gicient 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 cmttsnuu ;hgq6 1;4n o*ksnl08ircle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 tun k6n;t4nq so8m0 usg*1hl ;m/s?

  05.03: What is the centripetal acceleration of an object i9my buvf-)y2(mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a seco2uif9-vy) mbynd?

  09.24: A point mass moves along a horizontal circular path of radiusvgfd;)nio b. era03+m 0.8m with a constant kinetic energy of 128J. What is the rde .+ b3)fino0 mg;avmagnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string atsmk+vl4lov7/lf6j*+ ubg56 zpc 8hl nd whirled in a horizontal circle a8ufllo4 ltbg cmvvk5hzj7 p6*/s+l+ 6t 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 unhlah mkx7 c*10iform circular motion. Which of the following statekl c x1h70ah*mments is NOT true?

  00.19: An astronaut in an orbiting space craft attb cgj9lu2 5a. v+mx-m osr)jc2aches 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 macrx l s5)j +mva.m9uocj-2b2g intain uniform circular motion would be

  07.22: A mass m is pulled osx d,xe43xfg/je9 2 aeutward 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. Wdgf24x sx/xea e3e 9j,hat 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 terrain, see figure :q 5 y.+qqepbzto the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature bqq+ y5pq:.ze R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hid.- rleg 98dxr)hq3ltll at 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)edr8 x dqg3-.t9llrh 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 ,.m*ap krn.0c5yoc romoving in a vertical circle at constant speed. The magnitude of the net force onampk.r0 ,n*c c y5or.o the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest fromm q05 ymq8.;wn* h(+m da3*bsvl yagcn:vijx. 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 thn80w:.q+lmgm h *c;*d ( nax.3qmybsv5ayj vie 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 -xjjl:ze)p7d w30f erzktk +6a string forms a simple pendulum. The mass is released from restkp)k zd0xje 6r+7et- zf: wjl3 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 through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber strm+ob *v o*c9topper moving at a constant speed in a horizon*ctmbroo9+ *v tal circle. 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 to an i 9etnfu c*/5hcuwi9 p;/dksh7 h qf;l(deal 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 /kunc9ch*w;9fus h h epft7dlq /5;i( hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant 2o3 i0 f zjhxlf:0uss-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 it is at the lowest jxfszi30 f-:2 lsuh0opoint of the circle?

  14.23:Two small identical coins (labeled X andY) are t5)nbp ghfe:sxu yl 9h6gk,5 8awe+d 1at reston a horizontal disk rotating at a constant rad:,n)y h8fg ah5kb+5 l9tsu p1ew6e gxte 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 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 h- 7f-* 0mp7lltmrwuk string and moves about the string’s fixed end in a conical motion with a constmul- prk-0ml*w7ht f7ant 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 unifok2;d ( oqnp q6pa2o6z6refnw1rm circular motion as shown in the figure. The string to which the m defoork q6pnap(z 6; 1n2wq26ass 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 (mg cyurf:3 p: e,xy6p(j nmi730.0 cm from a horizontal disk’s center. The disk starts to rotate from rest abop mym,: :ip(gru 7x 6(3nceyfjut 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 = 3z-i3 xm06vqe,tto cd2.0 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 with constant angular acm33di6ocx0ttq, v e-zceleration $α =5.00 rad/s^{2}$ 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 speed 171d072dbs/w vw 5i4rpg ha tro-.0 m/s. The object’s speed increases uniformly until it has moved cou 7/gswdrbpdv0 a5oht1 2i4r-wnterclockwise 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, with initial speed 1 -iep;dntspcs*) xp);qq o ,7n7.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through ts-7;c,ip;o n*p )dxsq epqn) 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 tr*h +kywpxin ) 6cu51of a bucket. 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 tty1p*i 5)cr6wkx+ hu nhe 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.