95.02: An object shown in the accob,by6.fmpi0o g*p4a5aq uvadg*j) 2d mpanying figure moves in uniform circular motion. Which arrow b jpuf56yp,d04i o bag v*)gm2a*bdq.aest depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris W52l ht8ioscn1w9p: q4 7neuwjheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the to nplh4:75 q w28ntcw1uis 9ejotal force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in ao6g/:4j qg3uha7cvwq circular path 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. Point Q is exactly ha6 jo/uqag cvg:7hqw 34lf-way around the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle cp bh8hebvotx r+:) j53ontinuously moves in a circular path 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. Point Q is exactly half-way around theb )t oh+evbxj5 8p3:rh circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constant speed arou c:wdy32zm0e hf+mm 1vnd the vertical circle shown. Which arrow best indicates the c2 y0m:e+h1wm3dvmzf direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass/vnyvl4;w;o8 m bs08lvb*q bo connected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s b;v n/y4b8;0 omv lw *vqbo8slpath 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 co;g(5mqf28 ysfo a8fye +jo2h nnstant speed around a horseshoe-shaped path as shown with the arrows in theff as2m;f+y 5goyqho8j8 e 2n( figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon pbn7 gxmyh;-n -erform an experiment with a simple pendulum that is released from the horizontal position at rest. At thehb- nng7 y;-mx 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 of a ren-emq8 ycwkaflwa2+h-v/ue*i) )6 w ough turntable as the tu v nhm )+a)i-cfqweewayeu8w 62l/ k*-rntable 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 i)ijt ynp7(r4:udc2l *l;qdjf ;-e;ujmj 2wil s necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal f4mul:pfcw7) 2(;l u*ylji q;;2i e rjnjj -dtdrictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an objectck i) nc0x91egq56pp .jes6: 3elmgqd (mass = 50 g) on the end of an 80-cm string rotating at a co6 elecgdjq )s p0n9:ic.ex3p5mqg61knstant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radimbu6 vc9q8hfesh;tq8 sc-- 5ous 0.8m with a constant kinetic energy o-oc-e8 6 q qtch59h;mf8s subvf 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 0.80p26pht d 0na.cpwac.6 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The woc0p 6a ctdh6n2.p.w aprk done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uy (qijkf72d6jniform circular motion. Which of the followifqj 7kjd(y 26ing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attachesw oj,d; 3 prtiab);hu/ 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 sd );iuhb/3poj,rt;aw tring 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 ofki7: sle vunnuqx3d5f 0v g*z-0,mmg. 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 the7 u.: qkm,einn0lxzuf 0s5 v gm-*dg3v tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road i*z4/t-etb6+q(xpnwgi k wer 5n hilly terrain, see figure to the right. Assume the 5(w+x bqknet i ptrz/w *-6g4ecar 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 weightless:

  17.10: A 2000 kg car movesgz7c+rze1vf f 0ex*,t over a hill at a constant 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 magni ctfe1x0f* ,+v rzegz7tude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a verti6utp9 *7 5ji dj5dwuq hyf2gax.+v m42 bkfp4fcal circle at constant speed. The magnitude of the net fo2 d.uyfv 2qbdxf6kp+tp54fu49jhim5wg* ja 7rce on the sphere

  11.47: A simple pendulum of length Lhasag)rl6*mn9 ngx,zod1ty+z 2at0bhuz / point mass M released from rest from the horizontal position shown. In the absence of air resistance and friction, the mattxn0 rhz,ng9a z/yg 6)od2+zm*l b1uss 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 p/d ,cz4 0qsjro*dk hgd ./v6blendulum. 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)do/jr,kzdq* 6chb/l4 s.v0g d, 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 appfba4yp(;5 acl6a gha(lied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made s4ghalbp y (f(;c65 aaamaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface,dl ywn w.qoh 4h9j84q* 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 doubled to 2M. Ifwjqlhyq48dh o4 9* nw. 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 masgyh u(42p( rfcs with 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 u(prhcf g 42(ymass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labelf k5j1vn himgi;v.-bvh3i(, u ed X andY) are at reston a horizontal disk rotating at a constant rate about an axis per.ii -ujv bi1 v35k nh(fg,;hmvpendicular 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 connected to thrty vqfi/ 9:0ez7 xz2ae 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 ozqxya0 : 7i2f9v/rtezf 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 figurh/i) j935bn2xghnl2nc bg j3re. The string to which the mass is attached has a length of L = 3.00 m and fngh lcxn h2 3g2bj3)j9bi /n5rorms 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 horizonhu +2ucl)n2wetal disk’s center. The disk starts to rotate from restul+2wuh2 n)ce 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 =1.75 m fra vc+lr6(/n 1/on4jrsrvc a 4pom the fixed center of a disk as shown in the figure. The disk starts rotating from rer+ 1v/acn6vjrol 4sarnp4 /c(st 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 circle8q63k- zs (h ih-brj ,0kioejm, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it j er380mbq 6ii-z(jkh-,sh k ohas 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 1 g(emg )z,3pgd7.0 m/s. The object’s speed increases uniformly untz,p egdg)m(3 gil 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 of a bucket. The bucket is spun 88b;guu h/hk bd5i 8 px:2aqoiw45kikin a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves ju kuq5 gob5i:uk8 2ab/p8;xhi4khd8wi st 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.