95.02: An object shown in ;orff:.a g,)g t8j qf sxe3twjs+d2i3 the accompanying figure moves in uniform circular motixfrqtjt e+)g:.82osffj 3a; , w ds3igon. Which arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat te hfl 828 cszqt dj+0i7g3i1wbhat rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction t8d20s8h3 icqlez7b+j if wg1 best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path1nr1 a q/i*byb at constant speed in a counter- clockw/*biya1q brn1 ise 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 constant *+ xspwgj 5wb6d4bokqd8uq* ;speed in a counter- clockwise direction. Consider a time interval during whic odw8q*gwj ubp5;6*dkxb+ 4sqh 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 clockwi0z sq+505nueewmr2x,8 q ie. li0oppu se with constant speed around the vertical circle shown. Which arrow best indicates the direio pslqqp0 uzm0.n+w2e 5 0x8e ieu5,rction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smallrx rpt2 1l2.fn 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 latxp2 rlfn.1r 2beled P in the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves wi4d)rnknr-nxg6aop. h,w.s/ j th 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 of the average accew6r 4s)n o./k -rj,nxghna.d pleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moo6s/ 6)yl-nw 3fbcxt pln perform an experiment with a simple pendulum that is released from the l/ -bp )wn6ycs6flt3xhorizontal 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) poikzj1dn +5m5bk8ekm8 j nt-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The period zebkk 8m85mj n1+ kj5dof 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 ol o -vie/1p8/ev 5mp4bso(re1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface vi1//o-ms4olprep8( v5o ebe with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object ( i,q1k r25wf*vwj rm-dmass = 50 g) on the end of an 80-cm string rotar1,vw5 m-ji w kr2qd*fting at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m wi7okof4u+x( mb kj+ y,hth a constant kinetic energy of 128J. What is the magnitude of+kkj7 hy4+bu(omo , fx the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached fz6y.x+b ht+vt zz9v5ul 3y 9rto 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 of zh.+ 635bzu9 ztvvlr+tyx9yn the ball during each revolution is:

  99.22: A child whirlsi3ws 0)p9v(h n/ lnuae a ball at the end of a rope, in a uniform circular motion. Which of the f)3hnau ls9we (/inv0pollowing statements is NOT true?

  00.19: An astronaut in an or 8u*iam:xj ;v8(wakc fbiting space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of the circle is r, the speed a fum x*wk8(8vi; aj:cof 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 p:m74s (p uy*ypomdaxprykqyb 8 9 u(9*ulled outward until the string of length L to which it is attached makes a 90- degree a*:d7pouyb9 4 u(yp pqma9*8xyrm k(y sngle 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 arc?

  94.15: A car is traveling on a road in hilltr ppotbhd/;*.)km4 gywe); oy terrain, see figure to the right. Assume the car has speed v and the tops yo.)e4d;tmth;opprg /b )kw* 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 hill at a constant speee o6pn6xh etx -/a4drler 1:a4n-jw r0d 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 -xwt0e-r: rnl ea1 ne6 ojd4ar6/hxp4m, 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 i4cyhx+- zc hl.s moving in a vertical circle at constant speed. The magnituh4x-.ly zc+c hde of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M releasel;bmw)vnm e))d 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 gravitational force acting on the mass by the earth, and F represent the magnitude of the net force actin) )wv)lnm;be mg 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 connectedk(u5; h3rc39onqi- 9 mb xim*u yjs,jo to a string forms a simple pendulum. The mass is releaseo3*9icmibhxj 3-5rnkqj 9,muys (u ;od 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 through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a ;jq)8-yw; pa4duurv p rubber stopper moving at a constant speed in a;8u ; u)dwqp rpyj4va- horizontal circle. 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 a frictionless sury aaq3ci* ;hn:r01*mhu6 x ;t lyv*up-kdr q;qface, 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 m3t0mhdqx;6* rra uvyik**ny;hcl: a q1;pu -q ass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 3m q9c) zar1cv.+5o9p1 o oyvye.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is9v .zvao )1cmeo + 5yycqp19or at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal 0a6vhtfkm4cri)mz9* ygaxbp / t2, m 5 bdi*v2disk rot5my6 bmmvd p), hx2t ik/2a*t vrz0ci* 94agfbating 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 end of string and moves about the strinimwm.f*y 830 v2v/extn4ransg’s fixed end in a conical motion with 0fvrn2e3 8w 4m*yts. vnxia/m 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 in uniform circular motion as shory(2-3 wzn7dr9o bqb +e0c- ky:gwxpvwn in the figure. The string to which the mass is attached has a length of Lxwvc0oy3r +- b:pdezq2g-7k b r yn(9w = 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 disk’s :men .z*pf/i 717wk y*zvsefgc os00hcenter. The disk so .1fs* fhk/vswn:y e7 0 geiz*p0zm7ctarts 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 distabdkl0 7ub)g g/nce R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with cons/g0)7 kbldgub tant 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 inxlb oe:8z lb6oy2,jd+ itial speed 17.0 m/s. The object’s sll8 ,ydbox2jez+ 6 :obpeed 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 speed6vvcgg e*v es;:)r (xg.g-y qy12cq mx 17.0 m/s. The object’s speed increases uniformly until it has moved countexgq gmcc6;)(v: -ey 1yg sgrv. x2veq*rclockwise 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 restce3l(1 pn pn4ouuo1y- s 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 moves just fast enough for the block to remain in place in the bucket. Whenu4 3unlppo( 1c-oy1ne 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.