95.02: An object shown i 12a(y6gg bgekn the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on thgg g1 (keb26aye object at the instant shown?

  05.31: A child is bel:,n4x nxj gq:cted into a Ferris Wheel seat that rotates counterclockwise at constanxxn g:,q :c4njt speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a .5 e *klx g+lyw1 -1);vqbu* fgfwvhz7d(njslcircular path at constant speed in a counter- clockwiv+7ygz* 1 wl1x hfqd wgel*; k5unvb-j.sl() fse 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 msmn36s((w oyi5 ui0wd8 us c1voves in a circular path at constant speed in a counter- clockwise direction. Consider a time isi83vsu6yw(csu 051 (woid n mnterval 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 the verticalc 6cyrdsol92 48dx62 (mpsfjz circle shown. Which arrow best indicates the direction of t(j69z rdfp8cs 4cly2 xd62msohe object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to tp;.cx o xseo6ahll75: he end of a string counterclockwise in a horizontal circle above her headx6:o.7;coalxp sle h5. 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 constant12zz qu,s-48qkegob u 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 averag-q,geoqu z1s8k24bz ue acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform aa(vw*zp oud 19s,f7 enn experiment with a simple pendulum that is released ffa ew*9(odvz17nusp,rom the horizontal 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 2.0m from the center of1.bbkvd fn61ihv, ;oey::m 6xhm:ws ycw+hq , a rough turntable as the turntable rotates. The perv: :evh kmh6hm+c,ybsow,df1n1w i : ;y6qxb.iod 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 i n+ s8r+iyc4e hfky1(fs necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionle1 n8ihkfs ce+f(4+yryss surface with a speed of 2.0 m/s?

  05.03: What is the centripetal vf.;40 njxylb((wanm acceleration of an object (mass = 50 g) on the en(;j b(4n mny0.vlafxwd of an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizoa- w hi*ra/nlf1alu(/ymusxsn, 8x oi2*ot4 9 ntal circular path of radius 0.8m with a c 1mru/ t4xosyni/hnl wis2 -of a9,a*alux(*8 onstant 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 tozav0c 3p.o ha86q5mai a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the3vmaa0o68i ha. cqp5 z ball during each revolution is:

  99.22: A child whirls a ball at thep*s.xaa;j6 mb end of a rope, in a uniform circular motion. Which of the following statex ap;s.*mj6a bments is NOT true?

  00.19: An astronaut in;by xw6n yjeuef;.f,1 an orbiting space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of the circle1.;e fy;eywbnf u6x ,j 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 outward until the string of length L to which (gq 9;8eec .crz9aon z58a fcmit is attached makes a 90- degree angle with the vertical. z8er q(g c8a9e9f an5cmc.;zo 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 p r0.r 0gy/d6),lrp agwwci w2road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottomr,p/)w0.gr 0arwcw2 6p lidygs 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 hilj/su 9 fx,gsf8l 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. Which one of the following uf9,g sf8/xs jchoices best represents the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertica. .yn/81nn1a gq,fxhpmbu9 pm l circle at constant speed. The magnitude of the net force on the m.fbyxhgump8 91 / an,n.n1 qpsphere

  11.47: A simple pendulum of length Lhasa point / a7v( 5bugocsmass M released from rest from the horizontal position shown. In the absence of air resistance and fsgvc /u5b o7a(riction, 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 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 pen y+kb+l,h4vf ndulum. 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 swings throu+y4+kvh lb ,nfgh its lowest point?

  04.41: A centripetal force of 5.0 newtons o z8uyr,uuw .kv6k+g 2mhvl(n,-;ay ais applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happens+aal; -u,y2ku(ury k86z.nho ,vgmwv to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connect)zz-:k9wo x);j a ywszed to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds it at this :w9 -x z )wk)jzyzsa;olocation 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 3.2(g*nvzi4sfmp-y t95e4 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 point of the circlet-z4in95*pgsye v (fm?

  14.23:Two small identical coins (labele fe: 0zk7dv5q dzf6bb2d X andY) are at reston a horizontal disk robz6v07q5kd 2fdzef b :tating 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 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 en+:8 yxob6q cjysz.n*o d of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The s o8yqnycz: s6+ox j.b*tring 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 motioe(wrkb3w tgo4q5a21vl y .a3on as shown in the figure. The string to whoqwl .agbw3t2 31e4oa(5 yvrk ich 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 j) dyr+fw1- csat rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular ac -dsr1wjc+f)yceleration 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 =12 cinzga+e r vxopd*n6y3,5.j.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest wito r, njx.a2y+ pzen 5*gvdci36h 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 initial3/n z rvr.i)6ebnn x/t(j ov.o speed 17.0 m/s3/ib)x.r e6/o.nznvo(j v nrt . 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, startin z .6w+a/rupdng at the top, with initial speed 17.0 m/s. The objaur nwz/+ .p6dect’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 blockmn vtu0,q8us3/n aqn0 rests at the bottom 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 movequaq vs0/ ,0t n8mnnu3s 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.