95.02: An object shown in the accompanying figure moves 3g;j)dt,d knain uniform circular motion. Which arrow best depicts the net force acting on the otg3kd;d ,a )jnbject at the instant shown?

  05.31: A child is beltado2 - -v9bfvr mwj67red into a Ferris Wheel seat that rotates counterclockwise at constvjd a726-9 wbm fror-vant 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 circular path at constant spe-jlv-l(z uho rxq89jx,4 q 5dbed in a counter- clockwise direction. Consider a timq- j,(zbx8hvqr - 94xlol duj5e 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 p8+*:)hlq txgp4z/ 9pykhuzk lath 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. Poinzp+kg*k/9z h t :q h4y8llu)xpt 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 clockwiiosv*9im3 o: lp2j,1ey xi*tfse with constant speed around the vertical circle shown. Which arrow bos iyjmvpx:i e*i f9l 2o*,31test indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end -m7k 2uime 4/n vryy0 suzq,8yof 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 mu mqvz2ky0suni78y re-my4 /,ass 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 arounm:1 4mp.jdmw;owwe x (q abn+*d a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices ;w4:doaj(pb n*1+ xwmwem m q.best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on tddfjg zts5;h43 qe/ qb9 ,(lldhe Moon perform an experiment with a simple pendulum that is released 4fdj(ts,e hl;l/g9z 5q 3 dbqdfrom 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 lgwtm m/sk(b,1*y9 m mof a rough turntable as the turntable rotates. The period of the turntable's rotaksm,m/lm* t9wg1my b( tion 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 ned fiwg4nyu 7 f3*vv1q6cessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frf f1vnu*qigw7v46 y3 dictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an objo mav-2ygq9kv )y3j2iect (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times kgo)i q-m9 y3vaj2v2y a second?

  09.24: A point mass moves along a horizontal circul.jkexv:0r)- wsr au 7gar path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it mw g:rx07ru.sv )-ja keoves?

  96.24: A 2.0-kg ball is attached to a 0.80jdfvtk a051 qhm,0 o d.xz4gg, m string and whirled in a horizontal circle at a constant speed of 6.0 djqd xg5k,gv z1,00aht f.4omm/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 rope, in a uniform c.so7h5p/e gt rircular motion. Which of the following statements t7go shp5./re is NOT true?

  00.19: An astronaut i6ewl +/jrlan*77 yts jn an orbiting space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius ofe ly77j6stl/ar wn+j* 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 stringts u;oq) 2+ww+soz4 cd 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 string when the mass swings through the bottom ofth qds2;woz+o)cu4w t +se arc?

  94.15: A car is traveling on a road in hilly terrain, see figure 8tqg.fh /phup9q (i/wab*s. dto the right. Assume the car has speed v and the dspbh9*tuqpqfg/wh./a8( i .tops 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 speed of 12.0 ebn:hf7u/k, s m/s. At the very top of the hill, the shape of the road can be approb/ u:nf s7h,keximated 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 verticalnwzr. ck+p/l*1szl 7b circle at constant speed. The magnitude of the net forcekr/7 w l+1zlzbpns *.c on the sphere

  11.47: A simple pendulum of length Lhasa poin x u;wrc)0,0-ypkep,h 4fxyfpt mass 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)uyxcwx, p0f4-p yp 0,hf ekr);, 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 f, o-g1o/c9vi.v 7knikezzpnco,6 ,jworms a simple pendulum. 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 through its lo1-e,ncjkz9,izn w 6.oov7/ kv cgp,io west point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper moving m018jaiocbb 2q+ce5l at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happens to the speed v, and the freq0 5bcelco1 aqi j2+mb8uency f, of the stopper?

  05.28: A mass, M, is at rest on a frictinh*8vlvb5f3 0/vchosc0p w 0nonless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds c3lncon0h/ sfwbv008 v5h p *vit 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 mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant sp39hsk v e3w(l7kvzg- eeed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when iz w9-s ehvkl( 3gv3k7et is at the lowest point of the circle?

  14.23:Two small iden k7h u)wgfqpi1+ hgi;1w4-zgu tical coins (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 d) 7p1h+ qg;zfiui-wgk h1uw4gisk 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;nplb-j ,,rjrr)ws8 yl1nu k0 moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a length of 2.5p1;jry lbrn0 -s, krn u8,w)jl0 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 uniform8*fz: ava uamp/(5r of circular motion as shown in the figure. The string to which the mass is ata(:f8mf5v pr/auz*ao tached 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 fm7)lcb 9.sj9lkl o(i30.0 cm from a horizontal disk’s center. The disk sts oji (9kc7f)l9m lb.larts 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 distance R =a2,- ey .qrzg a fy/ovbi+6qb71.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from b/aoby z.a7q 6q-r yf2vg+,ei 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 initial speed 17.l89j 9kc3yq0/opp tkq0 m/s. The object’s speed increases uniformly untilpykp039ol q jcqt/8k 9 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 q(us)4 8w+ k;qn2dxof ppr8hoi*3vw g speed 17.0 m/s. The object’s speed increases uniformly unti4qhoxqi wdnr;g8v*+o3 fup2ps ( 8w k)l 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 ouqrk mpwh6 )3)f a bucket. The bucket is spun in a vertical circle of radius L by ar)u qpk6mw3h ) 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. 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.