95.02: An object shown in i)0xfgci 6/ lb0 lzx2qkyqv*3 g(nqo 4the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the of n0 x /0l6lv2k q4b3coz(q *gigx)qyibject at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that roi)fy6t--ugpj tates counterclockwise at constant speed at an amusement park. At t yjip6g)-utf -he 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 speed in a 80lmk5+gbmfzy4 z f66c;i havcounter- clockwise db0z f+8vg4i;l 5a6yzmc km6hfirection. 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 moves in a circular path at q6ml5syhq+s. 2 l;v auconstant speed in a counter- clockwise dirul6q mq;y.ass5+vhl2 ection. 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 acceleration during this time interval?

  15.07: An object moves clockwise with constai ;6tcw,m xtrz6(:yoent speed around the vertical circle shown. Which arrow best6 ot,cr;y:iwmtxz6 e( 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 of a string countercloi/cbx(r68d m5gjt.4c 1 dj 2s(groqihckwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from above the twirling mirgg(8d6dm2j c i.x( /orh45c qst1 bjass. 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 af2nx vfj0z7 ea;njke f g.00a:round a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling fro2 zfa ev0fjgk:00.n7 f;axnje m Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum tha-z)c u8:u hzart is released from the horizontal c)uuzhr -za8: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 res w3pp/w.s ;laxts 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntlwp3 x/pa;w. sable'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 keeuz-v +6a:282h/nemn gsmdmko p a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frics mv+2a:/kmm68g ndu ozn he-2tionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass 8kz5chek1bc .-d/ nijwy: /x l= 50 g) on the end of an 80-cm string rotating ate:jdy icxkb-.8n z5 /cklhw1/ a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal we1pllh/ s,s ir -h8q9circular path of radius 0.8m with a constant kinetici 91ls,q8/we s-hh plr 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 ste1bvmzy/p ,9du5 mos +ring and whirled in a horizontal circle zsmupdo mb95,y+1 ev/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 the end of a rope, in a un,h sb wngs d0tlqm(;h;p;h.6d -e.vehiform circular motion. Which of the following statv0nwhd(bg;q; m esdhes h.h;6l p ,t-.ements is NOT true?

  00.19: An astronaut in an .*y9)bljg sviorbiting space craft attaches a mass m to a string and whirls it arlb* 9)vysjgi. ound in uniform circular motion. The 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 tbk.hx 308jl yhhe 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. .yhk0bjx hl8 3What 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 ry5 n)fggeln7m2m+ * tdt:+mzf ight. 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 :n*+tme5gmf tmg7 zdnyl 2+f) most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant spejy/6e 7 jk)xpu*b fhc.ed 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 o*j6c. 7kyu) b xpjefh/ne 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 constant speedrsf qta*c/*q 4. The magnitude offsa/*rq4ct*q the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M releasedd.g8 r s acdm/q2v ed405w3gfw from rest from the horizontal position shown. In the absence of air res8 v arcgq/ dwg0w d52d3e.m4fsistance 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 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 stringy+2n +v7sjklvv 7 g4xj forms 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 jv 7sl+vy7xg+k2j4n vthe 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 nmv,m r3ns/a.. xtzm1s ewtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius i., 1mamz. vm3sts xn/rs 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 frictionless2n3n9hln 3m bn surface, connected to an ideal horizontal spring that is upstretched. A pe3m b32nn h9lnnrson 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 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/jz: hq- rk2ndj8gbt-5q. k th constant speed 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 it is at the - th rd8qt :kn2hjk/.g-q5bjz lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a p *gzvq;)(7 conr8lythorizontal disk rotating at a constant rate about an axis perpendicular to th vty* ()gzc8nq p7l;ore plane of the disk and through its center. 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 end of string and moves about )0hf f7pjug3r the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a length of 2.50 m and fo30hpfrufg )7 jrms 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 ax skqz i 976xm5 o5l:5eqzhikk +m:uc7s shown in the figure. The string to which the mass is attached has a length of L = 3.0ok7i :xqq6zk l h+z u:e9s555mx7 mkic0 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 horis5 j9h60 hrv,t( fjimggdbb/-a. +6zs lec7wozontal disk’s center. The disk starts to rotate from rest about its center with a constant ao g6/s 6i7jthd9vlw-s mgz,b5(rf+cbeh0 a .j ngular 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 :u6.ckx1re v pob yp-0with mass 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 1ykx :ue0-pv6c pobr. 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 movesh )pw k7zl ff24s xvo8wjcd332b 8a:nu in a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed sab3pj7zcu8 f2:n l)wdo h wv3 xf2k84increases 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, with initial speed yyelkx+ dx0/.17.0 m/s. The object’s speed increases uniformly until it hasx .lk0y+e/dxy 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 bu) u-r9hv aatx-+bp5 4nj53 fbmoo 5czicket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just fast -h5a35baj + oc)bv9t5fm-ur4i xonpzenough 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.