95.02: An object shown;0z ybm)f 6isv p7o+wi in the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instaniim0 7;o +zf6wsp)y bvt shown?

  05.31: A child is belted ii bw*,cy+th .d)x xae3nto a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat antcy+he.)dw i a,* b3xxd belt?

  08.14: A particle continuously moves in a circular pa 4+ aq o(urd-irq*o*muth at constant speed in a counter- clockwise direction. Consider a time ir*q*ud m4qiao o( +ru-nterval 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 spedvb,s*r,9 v9 nra+ttved 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 circlet,nr9 ,*9r+ adbvsv tv 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 vertical circle 2d+jb+ebi 4yyshown. Which arrow best indicates the directi4ej2+ bi dyb+yon of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end obw,h.) go 4p oefbkik.c 1o,v,0mcq9eyw1w l- f a string counterclockwise in a horizontal circle above her head. The figure shoc,,eph0b 1kf-)wlw9 ome.y qoob4. cw1,v ikgws 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 constant speed around a horseshoe-shaped path ahuo)wby*5x(c s shown with the arrows in the figure. Which one of the following choices beswyhcx5b)u ( o*t describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an expm yf952k( orzieriment with a simple pendulum that is released from the horizontal position at rest. At the momfy9 io 52zkr(ment 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 cenje4m,clc)-zhkj c4 s (ter 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 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the force of friction elcc cs,kj-h(zj44)macting on the object?

  07.19: What net force is necessaup 66r p py((v/cxm aujqk 9u,:ad7(tery to keep a 1. 0 kg puck moving in a circle of radius up:9u ((kx 7j(meq6ryp a6pav c,/udt0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the cm riboxa(x4vw;z- .3 *s1py klentripetal acceleration of an object (mass = 50 g) on the end 1 -zv.m op 4xx*a;lywib3sk r(of an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal ci+swwz:4l9* oukvs 0 abrcular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnik owba+l4uzs9sv*w 0:tude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attach/vtrsbt9qzwu- mwh-zq 8d* n m/2oq 85ed to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See fimz qdw-mtut8vzwq2/qo9 sb58/ nrh* -gure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end ofulx v90a 7 db7n8fq8yg *ha-kd a rope, in a uniform circular motion. Which of the fok7un7hga bvx8y0 q9f*a ld8 d-llowing statements is NOT true?

  00.19: An astronaut in an orbiting space craft al5 *)+tasejz7x/w sq nttaches a mass m to a 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 string isqn t7/5)j+az w*e sxls 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 stripfp o-xu4hk9a h9i0:zng of length L to which it is attached makes a 90- degree angle with the vertical. The mass is releasepxfh p ao9hi4uz:9k-0d 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 hilly terrain, see figure to the right.* s lsm9 o6wnch7dk:vxw92a 0e Assume the car has spldsxk* a:s7w0 n62cwom9v 9eh eed v and the 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 m/s. At8 z1s5;lpex/of a+edua1c34t cmmq0 f 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 t f0 le 13p ;+txsa faz8q1u/cd5mom4cehe following choices best represents the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere p+zvy ee,x8l9r x 6r2d4du9jjis moving in a vertical circle at constant speed. The magnitude of the net for y6dze9dleurr8jv ,xx+j94 2p ce on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released fr xg0b3. e nh2mv757idpnzwr*g om 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 ( v7xngp*mgzw3r7h ed20.i5 bntension), 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 formb7nttylhy0 .2c xw5x/s 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 lowest tl ct0b2x y.hy5x/w7n point?

  04.41: A centripetal forceshc0ohf2 i v+kw9j4 v9 of 5.0 newtons 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, what happen jk 4cow+hif299 0vhsvs to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a friy:q f1m2)qh6 a9c+mhoif5a)cvrt nt ,6-zrfqctionless 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 thr,tcoq5t6i62:f mz)+q9 h acq1)mya-nrfvh fe 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 3.24 m/s in a vertvmq gdosy4hq98d 1lqq9kd6 8an1dq 0/ ically-oriented circle of radius 0.75 m. What is the net force acting on the mass8q8dh 9qgy 0/61lokdq nm9v dsa1qq4d when it is at the lowest point of the circle?

  14.23:Two small identi6,,eg7 v5klrh(txxyv cal 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 disk is related by lrxk,(ye7 ,vv6gh5xt$d_x=\frac{1}{2}d_x$. 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 ofpjy f:1/v)du be b,*kg string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string hk*v,je 1)dp/u ybf b:gas 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 shown in the figure. Th..g;jvai biklwps 3vo;3+*jze string to which the mass is attached has a length of L = 3.00 m and forms an angle of l3;apo+v3;zi kv. igj.s wbj * $θ=50^{\circ}$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 horizw*bk 9hw4im6g ent7 ;xontal disk’s center. The di97*xwnw mt;6 4g kibhesk 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 M = 2.0 kg is attached a distance R,zgwrym. al,t duwo)+;c mbi (:m qu-/ =1.75 m from the fixed cen c :tu/; rbw,mo,almy+wq d.u(mzi )g-ter of a disk as shown in the figure. The disk starts rotating from 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 cwz;39ii+ehi0txba1 y ircle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise +x9wezh y1t 0 aiii3;bthrough 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 speed 0;qd(ur 6i 2n ef chs*h0;zzhs17.0 m;rdczfh (2; uqn0e6s*zs0hh i/s. 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 time for this motion?

  17.38: A small 2.0 kg block rests at trps qdm(n )*e*dz qpxh-0 /jz 1e3ek1u3xkh3 hhe bottom of a bucket. The bucket is spun in a ver)(m1r 3/1edz*0eh- 3upzdnx*sqj h hk3ke qpx tical 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. 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.