95.02: An object shown in the accompano5rvcux7 m2 91tg o1xhying figure moves in uniform circular motion. Which arrow best depicts the net force acting on v1t2o c51mx o7hxgur9the object at the instant shown?

  05.31: A child is belted into a Fj09pz7d tlz7cerris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the top 77cdzj z9t0ltal force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in 9eenkors(hph,9i8q(1 *x nb +kcr7nh a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the partkhne9 qc*he18,hokr7n(s9(xrb +n ip icle 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 speed g*99 onwz qn1hin a counter- clockwise direction. Consider a time interval during which the particle moves alo91z nh*oqn9 gwng 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 jfrj wf)z2z-k zm/3n/the vertical circle shown. Whi3zkffrj-/)zz 2m /jnw ch arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small f5lviqx-8 5ezmass connected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the massqxi8 f-e5 lv5z’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 horseshoe-shaplc8jfegj4 eyr-cav4 0. yl 7u*ed path as shown with the arrows in the figurc f-jyaelery.l *4gv4cu78j 0e. Which one of the following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on thekqd0 p icc+c9: Moon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagram withcd c9cq:k0p i+ $0^{\circ} < \theta < 90^{\circ}$ , 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 re5hbtn 6 np x;oba1uqa,dsiuot98j( ;4sts 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 and turntable is 0;j,; t ( oai4s9a 6d1txb8nnpuoq5uhb.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 6 c6r,rib ;ylik;9yeanecessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m,k ic6e9lai;br y r;6y on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accel, tt+gvj, jb+u9y ;efleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a 9t,uv ,+bt fyje l;+gjsecond?

  09.24: A point mass moves along a horizonuesah7 ofc o)l*2g z.8tal circular path of radius 0.8m with a constanofos27 czg* h)l8 .ueat 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 whirled in a hoi4+jj ixp2sitj3 vn.;rizontal circle at a constant speed of 6.0 si 3jtijiv2j xpn;.4+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 br y5 0rr5vlr3rope, in a uniform circular motion. Which of the following statements is NOT blrr v ryr0355true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to am se8m lovzt m*;6bq,x-c* 6hv 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 q; 6bl-ts,*mo hmemcxv z6v8*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 pul45y8 p tqau5 kyil.y-yled outward until the string of length L to which 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 stri558yyql i4-pt.yyakung when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hili7fe iwo( 2l :w5+wvna,qddt;mn bna4.z2 g*uly 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. The driver of the car a:mio;nwa i*t4g,b e+nflw(dzv 5.7dqw 2 n2 uis most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of cos xrhw:23h3s b+:tu 12.0 m/s. At the very top of the hill, the shape of the road can be apprht3b s+ocx 2:u3hw:sroximated 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 constantqfnw e z 8ob/hm*svrr)yf028- speed. The magnitude of the net for/ 8vf8-wh*rb)2eory zfqns0mce on the sphere

  11.47: A simple pendulum of length Lhasa point mxrzvk2)a+t;-/rm8x (g et.z(mw fuadass 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 mr( 2 wt)mdz(fv8mtuakrz; .xge x+/-aagnitude 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 pen61xrai v1l(p- .fiorvq3 zu-sdulum. 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 gr6r li -1o1fxva vz(isur-.qp3avitational 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 newtp*/ 0:v bae zvdebdv49ons 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 9 4veb:zb add/ ev0pv*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 saqh z3 2*w0(t0tnageb urface, 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 20g tbz0aqta (hn2 e*w3M. 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 co4/ji9e)::8upesg hbia o9ltmnstant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. Wha 9bs/89:jmp4ule e ogi:i)th at is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coinjb ok/9 nx6qb(s (labeled 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 distance of the coins from the center of disk is related by/k (bx nj9o6bq $d_x=\frac{1}{2}d_x$. 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 connect1,x fcp92d wt,;k;axz +qbsnled to the end of string and moves about the string ;datq,zs n9;x pkwxc12bf,+l’s fixed end 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 in uniform circular motion l3ijv ,b) +3ku dqk7:j xt dqpi6,2tyqas shown in the figure. The string to which the mass is avudk ji+36jxqt k3li):2d,btpq q7,yttached 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 mac0s dzk:wmc5, ss 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 angular accec0c:5m,w dzksleration 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 bim:(s+2jct ep-jp;b 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 pc:b+tpbe; smijj(2- 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 a180 hdrlj oay1t the top, with initial speed 17.0 m/s. The object’s speed increla0j 1ho r18dyases 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,e .ajn 0:;b -tegf y4zp2u 0lrii2j1tu with initial speed 17.0 m/s. The object’s speed increases uniformly unti1-bnyp t4te;.:22zja0u gfiiejl0 rul 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 bottom of a bucket. The buc ngi5 ./5* :hdvoolwelket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in:eh5g do.vl o/lni5*w 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.