95.02: An object shown in the accompanying figure moves inl* ji3f-ye1b rbo4qlda j(m9 1 uniform circular motion. Which arrow best depicts the net force acting on the object a( e dlor1-*l qfb9b a14ijy3jmt the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwise p-i-8;yuzf8h9 iqfsyat constant speed at an amusemi8 zi98u-pff ysyh;-q ent 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 continuous6:ju sptr/jf:ux b9x f 4h:q-rly moves in a circular path at constant speed in a counter- clockwise direction. Consider a tim9rpufh j-6s4bjfrqxx: u :t :/e 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 constaon od18j)8b3 uu dmvb)nt speed in a counter- clockwise direction. Consider a time interval duri) )mdo3dbu8v j8ou1 bnng 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 clcu.* dzomqs9z )7y dwvv;s q-t ,)gn8wockwise with constant speed around the vertical circle shown. Which arrow best indicates the directionyvmc-d t)z*nz)7,8vq w dsw9 qsug; o. of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass coplym hv885 a.wwe :3nlwbae.7 j3.gvonnected to the end of 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 mass to pass through the point labeled P egmha8v:8j vao 3w7ll3.wpenyw.b 5. in the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves with constant sp z*p nah(pc502ny yjj0eed around 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 acceln5j0n(h*z2 0j acpy pyeration of the car in traveling from Wto X?

  08.35: Astronauts on t siox)/+wgu f :mn.4hjhe Moon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At the momenfih4m) w .ng:x+/osujt 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-rb/rjjnicm7 exqj4c /z.s9 7/like object rests 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 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the force of friction acting on the objec.b7cs/e x/c4 z jnj/q i9jrm7rt?

  07.19: What net force is necessary to keep a 1. 0 kg puck moving in a circle ogr ;vf+tg8iuu2r2h ;j f radius 0.5 m tv8rhf2g +r2uig ;uj; on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an oblxk 871y* sqnf(e lo0oject (mass = 50 g) on the end of an 80-cm strq( oxlkfl1n* e80o sy7ing rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along *jszc*oro0tfob7*4 sa horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of4r0ozsj cbs7t*f*o *o the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is atta c- uf*fvz 60q(clq5pbmo)h3nched to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.v3fcfz u ql(m onb6qc5h*)0p-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 uniform circular motiz 2ezxj90s1o con. Which ofcszj9e0zx21 o the following statements is NOT true?

  00.19: An astronaut dw:swy d.6niuq+0ir2i25ut,amw 4 doin an orbiting space craft 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 v0oa imi2swd4+runwyd2d5.6:w, uqt i , 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 string of length L to w vz16sl8 ht8bchich it is attached makes a 90- degree angle with the vertical. The mass is re6bh s1vlz8 8ctleased 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 fie p 9xdb9zgn*(gure to the right. Assume the car has speed v and the tops and bottoms of the ezxb*9dnp9 g(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. At the vp (qn:le/wk k.ery top of the hill, the shape of the road can be approximated as a circlpekwn./(lk: q e 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 constant speed r:pst.gi)mh:vk av+lk1 33xb. The magnitude of the net force on the vpkbax: )i 1:mrsl.3kt+vg3h sphere

  11.47: A simple pendulum of length Lhasa point mass M released froyaov+3 ;4pq u ac hs1r,uw)qm ,2nylc7m rest from the hn+ 1vmpq;y) rl,u32 ycacuoq7 4was h,orizontal 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 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 pendulum. The mass is release tk9 :-)ub-z7tozp w0+fhmhdhd 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), -o- z9ht7ft+) zb:h0 wpmukdhand the net force acting on the mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtoe z+h* 3b :y2quz0ksqans 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, wh s: e*yazkhz3q02 +bquat happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless 7nd4bp 92 czl;p1e1z rdjovw2 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 4e9ozl nprvbzdd27pc1jw ;2110 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 w 9ctn60drr x+qith a 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 at9t+q0rrdn xc 6 the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizont r.j llyf.rj x(ph 39 +xc4(po2tdxr:eal disk rotating pxh ltc.(per2 lrr(d4:xj. f j3oy+x 9at 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 $d_x=\frac{1}{2}d_x$. 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 connecraig .5z;q8vor) inl :p9)fk sted to the end of string and 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 2.50 m and forms an angle of vii z8ps9)klq;or.ar5)nf:g$θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform circular motion as 6hfdqx g6e0. yshown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle qfg dh6x ye0.6of $θ=50^{\circ}$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 fn5dspxewr ( go/4r (z6rom a horizontal disk’s cente(o 4(/grdn5sp rz x6ewr. The disk 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 attadyt u(y x9m(3tched a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant m3 9t y((uytdxangular 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 initiwz/qad +psmyhlk366( omf 20qal speed 17.0 mo+ ywm3d pq2s0/a 6q zfhmlk6(/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 a circle, starting at the top, wiuua *s7gvg, xjm )n1;oth initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved cua)nvs ,x;mo71ug*g j ounterclockwise 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. Ti85w),ixoim dkgkq4326o :wd hbmzz3he bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest gzmkd): b823k6m xio o5i3hi4w,dzwqpoint 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.