95.02: An object shown in the accompanyh7tx wgb; /in,ing figure moves in uniform circular motion. Which arrow best degn/t 7i;xhbw ,picts the net force acting on the object at the instant shown?

  05.31: A child is belted icd):hi2qln jxlh 02 5cnto a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best xhqi:clj )5lnd20h2 crepresents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular pat0 s e2m+2lfsevh at constant speed in a counter- clockw2fv essmle+2 0ise 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 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 congox v(0i u+o8 r;eo+fsstant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point Puf;+ex+s0ooov r(g8 i 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 move*eu6z p ca1ggi +2p.vws clockwise with constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’.pwgagu zce+* pvi261s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a *xy:gm 6d ,z )ckntbtvsmk.0x1 ph1;ryxn3e)small mass connected to the end of a string counterclockwise in a horizontal circle above her head. The figuh xp3czm:). xrgt nxyk y;0 bvm1nk,1tds *)6ere 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 horseshoe-sh+s )9rlez(sxyaped path as shown wi sxsze)+ry(9lth the arrows in the figure. Which one of the following choices 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 s6rj4c.c f m,bbem+qps6hh02simple pendulum that is released from the horizontal position at rest. At the moment sp4cb6sqmsbe+0 f rmh,jh2 .c6 hown 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 the center of0 py(d0o-b:l/g tqray 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 coeffict0p ra qy l0bo(/:-ydgient of static friction is 0.80. What is the magnitude of the force of friction acting on the object?

  07.19: What net force i -ucba 0rw6*:sv xei u3gij0w9xhq( a)s necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frsa)xvbhj ix(i009c *w3a:u g 6rqeu-wictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acy p6eb4b f24kjceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at ajbe62 f4kpyb4 constant rate of 4 times a second?

  09.24: A point mass moves alongc- 7yz3rpx h0i a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. Whrxpy- i3h07c zat is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attachev17us, jx8qpgxp7hf0d to a 0.80 m string and whirled in a horizontal circle at a conss,18 7ph 0qxpxujf7 vgtant 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 uleo v+48r01f6yh duga ball at the end of a rope, in a uniform circular motion. Which of the followingo6u1eyuh+dv0 fl 8r4 g statements is NOT true?

  00.19: An astronaut in an orbiting space craft arm* 8mj h*,,xhow aqg1ttaches 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 spe,m ,1w 8*agqhoh*mxr jed were all to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulxwlzl + 73w8 zc70uty*s*z or+6w bbtba5*lltled outward until the string of length L to which it is attached makes a 90- degree angle with the vertical. The mass is relsozz5w8 *+zy76l*xblwa l*r+ tw7bu 0b ttlc3eased 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 z:rt(fd;5v w86 wm lf;4sqxfnc)9slpin hilly terrain, 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 weightless: cl;9sl r ;mqx8(wpfw dvz:6s4f 5tnf)

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. At t+ 6.0ke*1xb z:pbpcu5yqk yd2wu -l dihe 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+ .yubl6dkp - *w:k02cuxe1 d5pqbziy road on the car?

  97.13: A small sphere is movipt cv lvzw+ 1mo6+w1;kng in a vertical circle at constant speed. The magnitude of the net force on th;kw zmc+pwv1o1+tl6 ve sphere

  11.47: A simple pendulum of length Lhasa point mai*:t 5an6ax nyss 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 reprea:*iytnnx 5a 6sent 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 form15py4 ocs5.zf .pmgucs 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 gravitational force on the mass (W), and the necp m 54g z5socf.y.up1t 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 stgptp1wg*uxki8o 9i9h5 p1ca psx(opu1p/ -3 j opper 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 39ph5a9ixik / pgg18s-x1 ouw(j*pp1u pptco the frequency f, of the stopper?

  05.28: A mass, M, is at qlvu0a-c)o 8 8est q+jrest on a frictionless 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. s8)a c eljqo-8q+u0vtIf 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 conl7jg ug8muul1(tk :0 sstant speed of 3.24 m/s in a verticallyk: sul7ujgl 0g 8mt1u(-oriented 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 (labeled X andY) are at reston a horizo:d,/v.tovn )v6hn9 afdm6fawntal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the coinma/vn)afhdv o,fdv.69 twn6:s 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 moves about thmn 5fu o7v; t9 fevam8tycjn7/.. did: -h7bhme string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string hanb7h/ 7o.f9demjm-uv.nf5;7 hv adttcyi :m 8s 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 motion as shown in the figure.8m8w gg,tn q+h The string to which the mass is atntg, g hq8w8m+tached 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 30.0 cm from a horizontal diuvll( :a s8jy5sk’s center. The disk starts to rotate from rest about its center with a constant angular(vlja uy:l85s 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 *dva:rs5xq5k = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The vaxsd r: *qk55disk starts rotating from rest 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, start71sckpkp. at ,ing at the top, with initial speed 17.0 mtc,ks7a k.p 1p/s. The 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 final speed of the object?

  16.40: An object moves in a circle, starting at the top, with initial v15c-iysdra5 cl -h 8uspeed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angleu-s5rl8 v 5-h1yidcac 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 ofk rw 92lm5a7bw 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 the bucket. When the buckearwm 52wbk9l7t 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.