95.02: An object shown in the accompanying figure mokduh/ 1maa0:hves in uniform circular motion. Which arrow best depicts the net force actinmu1: ak 0/adhhg on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwisevycrw095 oor-3+ rqvc at constant speed at an amusemeqyc-9cr0w +ro vov r53nt 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 conting4glkb 1cp y5-g3z6juuously moves in a circular path at constant speed in a counter53 yk pgzbjul4gcg16-- 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 circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously v b:hnm5ely**xuy3(y moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circ v*:u 5lm*3byenyyxh (ular 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 kzxqk 4gfpa)-x 9ft :6clockwise with constant speed around the vertical circle shown. Which arrow best indicates the dixq: gt f4fzx -kka)p69rection of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass c m kl2te f-tai ,cj;)(33aw4asekbf( fonnected to the end of a string counterclockwise in a horizontal circle above her head. The figurea)b fs(t4fec,-2( j wa3f3ai ;l kmetk 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?

  15.23: A car moves with constant speed around a horseshoe-shaped pa v3 b;hg:+kbieth as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acc3i kb +:vheg;beleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simp/w,y 6zjg3cl 5kn9xo-xg3ppyle pendulum that is released from the horizontal posi5wy 9nkgc63/l-p ,xjyxzo g3 ption 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 objec: j7 bblsmp/j/n5yd(m t rests 2.0m from the center of a rough turntable as the turnta 5js(/dp /b:nbl ymm7jble 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 acting on the object?

  07.19: What net force is necessary to keep a 1. 0 o, ynw 7gg24jtr yhiop+p( -w1e p:7-e,oeudgkg puck moving in a circle of radius 0.5 m on a horizontal frictionless g+ 72 gw7:pwido j (1poehe r4y tog-,,yen-upsurface with a speed of 2.0 m/s?

  05.03: What is the centripetal mmei.j/ w*rul v;h8p.n*r 0 yb9mmnn*3phce7acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a c8 m9ehe*lh n. 7;r. 3r0in *wpncmm /jy*uvmpbonstant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circ l jr2da67xz0-1poul rular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting onx06j1l 2 ozrur-dap7l the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horix)4dw40emn7w c ;atl gzontal circlceg a4 mww ;)dl47tnx0e at a constant speed of 6.0 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 th9gkhf*z.d 6 x7hi ow0le end of a rope, in a uniform circular motion. Which of the following statements is N07 .lig96wfdohz k* xhOT true?

  00.19: An astronaut in an orbiting space craft e+jtjg2 yl)+rcl bt,7klo o ):attaches 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 loj+ ))c2j+k:l7gtebry ot, lstring 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 leng+-gs1e tr/clan x1l.f th 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 ten/g 1scr.f l1ax+tl-he bottom ofthe arc?

  94.15: A car is trave;m6 0 kz1 go 30 i0s4*qlubyanl/wxappllt)r ;ling on a road in hilly 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 is most likely to feel we 0lgkys zrxu 6 a1l003tw4/p ;pll;qi*onm a)bightless:

  17.10: A 2000 kg car moves over a hill at a consta;:t6hfbm m.wo;a oa )p 0vq-rpnt speed 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 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. 6-wm pb;;hqtfpo0v :or)am a car?

  97.13: A small sphere is moving in a/9k4k nyk (:;wjlrfm jg6z2ga vertical circle at constant speed. The magnitude of the net force on the sl nwk k jrf9(:/zygm6; ajk24gphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest from h1vxf ).,nn- fkcmxx;z3 ,ffmthe 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 magnitz .1x;n3fh,cfmv fmx),nxk-f ude 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 stw6e 21fgtd hm-a-iyw*ring forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the m yed-ft-w62i*hm1g a wagnitude 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 u(8a+ g4akpxq to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but+g4aakq xp(u8 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(50m2a* cozjkrjxl3 g 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 it is now doum5kjxcz30 2o(a lg *rjbled 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 spe1 0qd,dou 4.b99jpc orfy.zdmed of 3.24 m/s in a vertically-oriented ,cbjd0.do .1q4d m yzporu99fcircle of radius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) l5 yu.t13/e01qia ssneqwv5 :jqyu )g are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its c1:elyus05jn q)1ia 3sq. q/tyv uwg e5enter. 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 en .lg7v6qp4o;vj as/ qnd of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The 4 lpj;s/ 7g.vqnoa6vqstring 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 circ6 ob/eh 6:dwqxfxf-9.n 0ki rqular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an0x rd/hoqbq.- kef6 f6n :x9iw 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 aq x )teys: xwwx8,dl+/ horizontal disk’s center. The disk starts to rotate from rest+8xwq:x,ew l xtd )y/s 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 =ss)p :xn,9or: h rgn9y 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 fron hrsox gprn9y:,9) :sm 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, wzi/jd :4 5ozuxow/*zz exks44 ith initial speed 17.0 /zs/5:jzxw*xkod4iez 4 z4 ou m/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 final speed of the object?

  16.40: An object moves in lw (lfaap (69 /zqdmvr -xu5c3a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through a(da(fzwxu c 3ra9m/l -5l qpv6n 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 ths6ekh(2 saadzq3*f51.8nqx xd sq i 9re bottom of a bucket. The bucket is spun in a vertical circle of radius L 8q(xa*sqqr531xs9hnzk dsfi d2e6a. 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.