95.02: An object shown inpoo+8 x94m,,we2p:n unye./fhr qrfu p-x8dp the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the er,w.848fno,m pe +unpu :r/ qhx-po92pf xydobject at the instant shown?

  05.31: A child is belted into a Ferris Wheelp9 2pa9v(;xdbv si:b 97h 8fo1 dgamqa seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the a2hoi9;gf9 7qb(d v8d 9bpmvs1xa ap: total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular 08kyk)nacw/us5 lse7path at constant speed in a counter- clockwise directi/8k)e l nwsu57ks yac0on. 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 con34nhtz(u 2ymkq x,k )ztinuously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval durmz,2 kk3(q)zu4 y thxning 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 clockwict.+ tr:m+6k(buh bhqv 2 2csgse with constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’s insth2bmtkgr:qv2b +.uh6 cs(ct +antaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smallqb j u+sk,-gkk0;e tk2(znty- mass connected to the end of a string counterclockwise in a horizontal circt-k ,tjub-q ke;k2k sz(0gny +le 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 string?

  15.23: A car moves with constant speed around a horh/ 0. k;azcw kmpea u))(9knsvseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the directik 9 uhwz(k)es a/)av.kpcn0;m on of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an expw/19ao/pzzx6n sv8 hderiment with a simple pendulum that is released from the horizontal o6wpz9hd1z/vx/ 8 nas 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 rests 2.0mauk8eqltzf bbxv3 08*iab9(, 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 a bqb 3f( ivuz0*98b tea,lk8xand 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 /i- iymqllw 3sem)tkw2a -5n; to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless sui3tnki -m;we -ql /m5s)2lyawrface with a speed of 2.0 m/s?

  05.03: What is the cen:/t u9:tdf xjg o/qk5jtripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a sudktjt/j q5 gf:/o:x9econd?

  09.24: A point mass moves dhs5bmvt8 *- :7v vb wz:j;dfaalong a horizontal circular path of radius 0.8m with a consta z v*7vtfh:w-m8ab5:s dbdj;vnt kinetic energy 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 a 0.80 m string and b0u7ix-ds.0i o+aeh owhirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolutio 0o+- uo7saxd0h ei.ibn is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circular motibhexwrr9a( y1edg ,e54zt32 hu r((ebon. y( a( ge4r3uxre9 rh5(b,w1tzbede2hWhich of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craftf2w 02h f vdl.gqs0+wu attaches 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 requ+f .2l0gq0fw vh 2wudsired to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the string of length L to which it iac::4g hle:gss attached makes a 90- degree angle with the vertical. The mass is released from restg lhe4:acg::s 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 roadt ;zkq ,z:i5df in 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. Thz,5 i;z tdfkq:e 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/ss b47nc,d tpnllb.s + ku+z1j5. At the very top oz5uns 14.lpb+,jn+ckdlb ts 7f 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?

  97.13: A small sphere is moving in a vertical circle at con i m2 d2)(5zfcf -sluxlf584vram6daestant speed. The magnitude of the nmlxdiufdz 54l)f52c(v2sr a fma6-8 eet force on the sphere

  11.47: A simple pendulum of length Lhas u o uh;)aiffojpb*a8/ka ;4m7oyk9a4cr/v o4 a point mass M released from rest from the horizontal position shown. In the absence of air resistance and friction, the mass swings th;io*u8b/a 49 o;hkvf ka yprja7oc4/)f 4amourough 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 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 simple peyb6fno1n/x ty gd469 g/b hzj4ndulum. 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 /b n/44zo6 j y 9dghtxygnb61fthe 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 forc ;jr*o1; :g5mu a7un xfprgq4ae of 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If th f*xuura;;n4g57jro: m a pq1ge 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 id,lp; .p* ec0,ll k-yqyz qucl m9v6yi+;u .zvmeal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds it at this location by applying a 1vkm; l.*uz6+e.lmuy qil,ypyc z0v,c-9q;pl 0 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 sp+q egm4) 0upkbts4a)r6.ow cn eed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on cska)bo4)rpm q0t + gew.6n4uthe mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are qwt;i4 pf4pk31bu)-8xwx )pdcmdv5 sat reston a horizontal disk rotating at a c1 ds k43wc qp))f b-4p8i;5xdpxvuw mtonstant 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 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 sw.sg8 2v6edj ntring and moves about the string’s fixed end in a conical motion with a constant speed of 4.jn6sde g. 8wv20 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 uniform circular mo xpnxihau + qrae53).8tion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forxxrap+ e.)5uq h3in8ams an angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of m lmjw-3jc9)bpass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angulj9-b jcm3)pwlar 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 distance6q-snkf3 uv 0a R =1.75 m from the fixed center of a diuq 3f6v-nk 0sask as shown 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, starting at the top, with initicf:t88 usuqqpqoh)x s/w/+5wal speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an xs/uq ws+uq )h8 tw foq5pc8/: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, sia+bvs ;f )j+gtarting at the top, with initial speed 17.0 m/s. The objec iba;+)gfjsv +t’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 time for this motion?

  17.38: A small 2.0 kg block rests at the +hese 8svv 72s(-4,kb rrqpibv*ig( ybottom of 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 fob8y( e2,h+sv er(ri7vs4-p*bg q siv kr 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.