95.02: An object shown in the accompanying figure moves ini-12eg znok8:wl.u rz uniform circular motion. Which arrow best depicts the net force acting on the object at the inu-izelog.wz 1k2r n:8 stant shown?

  05.31: A child is belted into a Ferris Wheel seat that ,c- n,2uuzskerotates counterclockwise at constant speed at an amusement park. At the location shown, which direction bes-n ku, ,euz2cst represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuto (b/7.c ngouts,j(g ously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which then/ .sgb,too t g7j(c(u 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 constiv oit49m9w:d9qntwoj-8 t u 3ant 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 d 3 ujtovt-nmi 994o:iwt98 wqhalf-way around the circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwi+zde ng3h g4d ;xd0zyog+v a;:se with constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’s instantaneo+d g0;v4 zen;ga3 yxdoz+:hdgus
acceleration at the point labeled X?

  12.11: A girl twirls a smallx2dop0z+q u5j mass connected to 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 letteredzoj +5qpx0u2d point on the path should she let go of the string?

  15.23: A car moves with constant speed around/f:k62r7o hanqi3 qt/bhn vq 6 a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices2n :/knr63ob/qht7ifqh6 v qa 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 pen5vwv qlq,jj i,;*mmif)9z * y7:rzgmedulum that is released from the horizontal position at rest. e r mzifgw7q,my)j;9z,im5* vlv qj :*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 re7k:3ildgl xlm 9d ;cg2sts 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 fgl;l7 md d93c:gi2xlk riction between the object and turntable is 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the force of friction acting on the object?

  07.19: What net force isirmq*q b16: ax necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface wit1b q6qxr*im :ah a speed of 2.0 m/s?

  05.03: What is the centripetal accel )i zdj8x k*w.f u9w.u)dkzt2ieration of an object (mass = 50 g) on the end of an 80-cm strii )j*d wk9t z)dk.u2 .xw8ufzing rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius s*i g( u6l:ygy0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mas:gyu (i6 lys*gs as it moves?

  96.24: A 2.0-kg ball mf4-j; q xqas-is attached to a 0.80 m string and whirled in a horizontal circle at a constant speedjq;-xa fsm4-q 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 moti) *hy 8e9jmqtdj2kk -rrg7w+hon. Which orr8wh92 tqjed-j+g mykk*7h ) f the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attac0n6n hd/k domnp :et84hes 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 maintain uni8 n6 :hdpod4kt0 nm/enform circular motion would be

  07.22: A mass m is pulled outward 1u*(yr; 0n wduopes,f 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 the tension in the string when the mass swings through the bottom ofthe yuud0nops,;ref 1* (warc?

  94.15: A car is traveling on a road in0dtuprnj z/6 + hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the j +ztrn6 pud/0hills 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 12.0b0pp 9/ 3.reauboq2 iqrd8y;a 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 oqqb 3ope;0rp2rd abi9/y ua 8.f the following choices best represents the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant speed. Theo2 i.ibh5 9wbezp5h4jd0o6 w o magnitude of the net force on the iphhj o wio6 d.209zebb4 w5o5sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest from th6r sv-*xif ue6e 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 magnrveu-6x sf 6i*itude 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 forms a simplev.a3 w2xpb g6zjsqvg (/. -oyd 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 (/.- bavjx3zw.sgd2 vg6y opqforce 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 aba5. :o )dgjmstopper moving at a constant speed in a horizontal cajo m)a:gd.b5ircle. 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 mz)s ubc.s0jm7k6u3p vwl7 ;y a frictionless surface, connected to an ideal horizontal spring that is upstretched. A person exte) sm3ls 0;u7 .wvbjkyp7uzm 6cnds 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 constant speed of 3.24f9kcx5 n/hh6i ap( fc2;fac6c m/s in a vertically-oriented circlch f6f;p2 5(x/h6 fc akcicna9e 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 iden *sy)qvey0(nnxp, 2 c+ked0iatical coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk an0pdia ()y sneekxnq 2,y+0cv*d 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 string anltu2jsd89iw 9 m8fh0y(b+aylwfr9m 7d moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has afyh(w rw+ydsul89fj7mtl8 2imb99 a0 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 uniformgw3: rd-4caof1c.w hw circular motion as shown in the figure. The strina4d o-fr3cwww 1cg h.:g to which the mass 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 30.0 cm from a horizoop)fq9e dk8ap h 57zq)( wtn7rntal disk’s center. The disk starts to rotate from rest about its center with a con()a q98ntqh7 )5rpof7z wedkpstant 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 x:w*h ,dye1izM = 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 1y*d i:ehzwx, 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 ci +xrtgw+.4* izjcdz;hrcle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwised;+z r*xz.4+hgitcw j 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 t mgs 3o5)pqh9rll+*owi-ek7nop, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countercll* erp-wohs lg+o93)k7 5qm niockwise 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 is sput( uo,rf kj ym+/;cet1n 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;c/+ m r 1uytft(je,ko 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.