95.02: An object shown in the acco 1x8r ops88jtumpanying figure moves in uniform circular motion. Which arrow best depicts the ne tjxr8p 8us81ot force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that0)kuw x jc57bvwq 7sj3 rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best representswj )5k 3xjb7vq0wcsu 7 the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a cit xl56xj.lga,g8bn f19pam. wrcular path at constant speed in a counter- clockwise direction. Consider a time interval during which thegplwfa,a1tbx6 jn x8.l.95gm 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 cq aqgy3 , khx1:lhc:, yb;;sfbircular 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 poibhgl c;1,;qyxh: fqk:3ab, ysnt 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 consta20sx +jip: )y,bkj kaxnt speed around the vertical circle shown. Which arrow best indicates the direy s+i2j 0,pkkxjxb):a ction 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 countercloc1ip)vr.isu5 qcsv 7a51dl:fwkwise 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 pola u rf)i5cw571vdss qip.1v :int on the path should she let go of the string?

  15.23: A car moves wi;g4n 0sq 8 )vub.-bqvtxb s) rvgp(3rith constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction o vuptvb )0)v.-b sgi8brqg;n qr(x43sf the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon pe ,ri4mqtfp79 zrform an experiment with a simple pendulum that is released from the hor479r itzfqm ,pizontal 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) point-like object r1, ue hd/izct( ctr5( 6duklh,ests 2.0m from the center of a rough turntable as the turntable rotates. The pe/(d,kztc(h1l6 rdue5 uich, triod 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 magnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep a :j6cw))f9lwed/ (iz swzxf/ n 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless 9xf6w / wnszj(e:idz) l/w)cf surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an objef tx i(cq xba o(2mxoeg3c4//a:n)(olct (mass = 50 g) on the end of an 80-cm string rotat(mb2t 4/ oo(:3ea/inla f cxcxg(xo)qing at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m with nlm ar2ne0rvva27qfef+huj3* u+1c * a constant kinetic energ2f27hnru+a 13 e0 aqve*j+mlufn *vcry of 128J. What is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to (y9w0 gag 8r0t6crrrky2du+ o a 0.80 m string and whirled in a horizontal circle at a constanrd0+yu6 wyrtc2(arko89r gg0 t 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, in91 w(b+h7sda md1vh0j: plriu a uniform circular motion. Which of the following state:d9j+0b(mlv71 pwhui arsh 1 dments is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m totw 5 hgj 2n/rh(5+aqafh(ef-a sl0q) v a string and whirls it around in uniform circular motio5s a 0w(qhqr - fjael(hf/ nh2+tg)a5vn. 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 oumq4 x 7+v-hh8 j5maveetward until the string of length L to which it is attached makes a 90- degree angle e57mm4v-he hj8a xq+vwith 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 arc?

  94.15: A car is traveling on a road in hilly terrain, see figuhg0 j1myq7 -:qj+yontre to the right. Assume the car has speed v and the top0t:jg ny7 q-mhoqj+1y s 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 hi3uvzl5i/6 s+lu/w8ilh(qb ts ll 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 radius 25 m, as indicated in the figure. (lu/t s53l+l huvi /ib8 6szqw 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 moving in a vertical circle at consta t(askvpx;, +mnt speed. The magnitude of the net forx pkav;(+s m,tce on the sphere

  11.47: A simple pendulum of length Lhasaqnva7ep3sn :v/p0t fb(mc-/ w point 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 gravitatiotmqv:0f apbc p-w //v3ne(7nsnal 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 w9o2)3;kstrpi,s b)b+t c k bastring 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 gravitational force on the mass (W), and the net force acting on the mass (F) when the mass swkb;r ,si3)bs ttwa2ckp 9+bo)ings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubbi pyzcmk8;,nw5 lc )n;er stopper moving at a constant speed in a horizontal circle. If the same force is applied, buym cwz)i;8,;kcnp 5ln t the radius is made smaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is ae4: ob u;uduvr7.j lalu08t* nt rest 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. If the spring is extended back 30 cm from equilibrium, what is the necessary force applied by the person to hold the mass stationary th;ud74.l*bu0areu 8 ntuvl: oj ere?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 3.2( )2nkbcw7dgcwl4 k 9o ke,bv24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net cekwdc4 kwv72b )g2 b9n( klo,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 horizontafyxkch 3-,qyn b+;r43hyc mmv q2,. ral disk rotating at a constant rate 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 3 .hxy -,vkcqm4+2yqrbyra;hmf3, ncby $d_x=\frac{1}{2}d_x$. 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 endlaijr *q5)ly-p dmsxoe ms684 9 xj:g0 of string and moves about the string’s fixed endsl5oxyr mdag-04mp x8ej:qj6 *)s li9 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 in34gfk 1 hbdd dyjd yw588ry:.l uniform circular motion as shown in the figure. The string to which the mass isg d :bkj8wl4ddh.5yrf3dy8y 1 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 horizontaybb:e j uq f kg8-;ty19tm10uel disk’s cen tftq0:8ebyu - k;y1me1gb9u jter. The disk starts to rotate from rest 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 with mass M = 2.0 kg is attached a distance R =1.75 m mkz.8q u9x1 *e*dy ytk:yzc5f from the fixed center of a disk as show5e.q fuyyk* d 1y: c*8zxkmzt9n in the figure. The disk 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, startim6u* r/ivyq p;ng at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwisev/ q*r upm;6yi 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 submm:-jzzekv5 z2) 2 initial speed 17.0 m/s. The object’s speed increases uniforvj5 z2emsu-m2zk: z)bmly 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 k7s8 k/dnvh38 w+6yvt+tlp bzsg block rests at the bottom of a bucket. The bucket is spun in a verticavs kz3dpb6w 8hs ln++t8y/7tvl 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 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.