95.02: An object shown in the accompan*/ g14 a x6ugdmzcc1duying figure moves in uniform circular motion. Which arrow best depicts the net force acti m*ucuc dxg/16adgz4 1ng on the object at the instant shown?

  05.31: A child is beltswq3, q jx9;f6xny2p2ort3tped into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best qrw npxx3py 2o t,9t;36j2qfsrepresents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circulaq nih;03. jkeqr 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 point Q. Point Q is exactly half-way a 3enq hq;ikj.0round the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves myq :na9 ;k ,zhw80ty7dkgcalh/9pf( k 5 9szjin a circular 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 point Q. Point Q is exactly half-way around the an9tlwp cyygf8z;, h /0kaks(:z7d9 5 k9qmjhcircle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object movg foz(t2egny /n8a63 tes clockwise with constant speed around the vertical circle shown. Which arrow best indicates the direction of tf6tyetg g nna/o32(8zhe object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string counterclockw12avc.9 .e fg vp6qpmlise 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 point on the path should she let go of the string? q.vamec. gv p162lfp9

  15.23: A car moves with constant speed around a horseshoe-shaped path rhy(4 blh4+wp -of9gxas shown with the arrows in the figure. Which one of the following 9hb (f4r+pl y4-xwgoh choices 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 pendulum thatjkq- yo5p5jruhi+1 /u is rel j/1yj 5 uh+oqir-5upkeased from 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) poib ocil/a;2 ;sjnt-like object rests 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 friction between the object a/ j;osia;c lb2nd 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 1. 0 kg puck moving q23 fgi*;4*vpzyuptx xz 2c;yin a circle of radius 0.5 m oy2 ;4 puxq;pz *vxg2ft zyci3*n a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on t a96mnl z b clc,o18da0v7as*zhe end of an 80-cm string rotating at a constant rate of,vs c9dz7 alol 6a0mb1a8 *znc 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radtj1jvz8zn5uhc 90/v a ius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force a01j9cu / z5ajvz8hvnt cting on the mass as it moves?

  96.24: A 2.0-kg ball is att6c/ng q:; ii8d+ mn 5e+.cgidjhncz.yached to 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 the 8gqej+/5 ih g+cnc: n.i dc6niyd;. zmball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform j+wu. z6b9ybel+ml mj (5t +crcircular motion. Which of the following statemeryt5w+l.+ c 6(mlbu+jez9mjbnts is NOT true?

  00.19: An astronaut in an orbiting space craft0ac0)ilp:fi 7 8t)r aual vpy, 4sqa*j attaches a mass m to a string and whirls it around in uniform circular motion. Ts:a tljp,0pya f0i*a ica7v8url4q ))he 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 outward until the string of length L to whicbz2 u5gsu1x0q h 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 strinu1z x0qs2 u5bgg when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the riuwzhq7k) :qu/ght. Assume the car has speed v and the tops and bottoms of the hills have radius w/qhu)uk :7 zqof 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 12.0 m/s. 7vyd.n,weg8(. gu hwgt5f 7ixAt the very top of the hill, the shape of the road can be approgt.h e.7wy(fg58nu xvdw, i7gximated 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 idm6 mc um5+0qus moving in a vertical circle at constant speed. The magnitude of thecm+d m56q umu0 net force on the sphere

  11.47: A simple pendulum of length Lhasa point masdc:*x8g.vaz b, 1/:mxj wxacus 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 gravitational force acting on the mass by the earth, and F represent the magnitude of the net force acting oxjmcz8g w1 ux, :b ad./:*vxacn 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 pendulum. The m5cqvq- 11: umxm bbgi(ass 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 mqi- v(1 5b 1:qgcmxubon 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 new00j4+sbkc t;qbr am-etons is 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,temcr0;ba+bk jsq-0 4 what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is bxr;3:y2c /q u1w9jjx0weov o at 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 v1/ ub qo2jxe :0rw;co3y9wxjit 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 3.24 m/s inpc )gbi44tol*s wi,1wjrj3qi j 7rp;( a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowesic wtsi4 ;irw) *lj4o(jjqp r17b,3pg t point of the circle?

  14.23:Two small identical coins (labelm(hl:1 p hc0xio y+)fwed X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distan myoh xw0ifhc pl:(1)+ce 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 connectedbggfmd q6(3s+jq: (he dkqa+xu r7 *2u to the end of string and moves about the string’s fixed end in a conical mot+q6f3:qubdru2 (s+h k7agdj ( mx* qegion 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 dv2ipi)f pw5) is in uniform circular motion as shown in the figure. The string to which the mas) fi)5i d2vpwps 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 horizontal dis 33l7lke cx 4zllq9n4hk’s cc3 xn4z 9l eql4lhk3l7enter. 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 xm 1d6d2w hb,vvp28ke M = 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 starts rotating from rest with constant angularvxd 8dw6h e2k,pbm 2v1 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 inif/ 6yp.wost(stial speed 17.0 m/s. The object’s speed increases uniformly uspw s(.foy/6t ntil 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, withk-+ lv:b tq9sff+q,n ihgj.7c ;-f)pqh: ragh initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throu-n) g,hqhf s.-kb: l;v9gari+ :jh 7pqf tf+cqgh 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 gr- .,yjn0ndch6jt76 skmr 7*zqx, qdyt cy4-the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reachj-0r-h*tkzx jynm7ytd.6 y64sn qr,cd,q gc7 es 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.