95.02: An object shown in the accompanying fi;w n3crv;ln 2c h2kj6hgure moves in uniform circular motion. Which arrow best depicts the2 lhr6jc k2c3 whn;nv; net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates q 3niky5.da 0.fb1kb6x9una/dpx9cgcounterclockwise at constant speed at an amusement park. At the location shown, which didb0p6 a/xxn.9.9qny au3dkg ci 1f 5bkrection 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 f mpz ;57 k(3vej1xps5bnefs2 counter- clockwise direction. Coex5v f3 pke; 2mpb f1s57nzjs(nsider 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 continuousl396cdssrtnh ; 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 circular h3sr n6;c9 sdtpath 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 constant speed ar)bqdlv:: s2 9 zhsh-oiound the vertical circle shown. Which arrow best indicates the direction of the object’s issh)-dh vq2i :b o9lz:nstantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smalle) t 9pidihdik9y*2,y mass connected to the end of a string counterclockwise in a horizontal circle above her head. The figurye* d 92thd)9ii p,kiye 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 path asbuay 9i /oz4s(cyw48t+jyf e1 shown with the arrows in the figure. Which one of the fowoea9f+y4( 4yi1 bt8cs/z jy ullowing choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perw8+)gv 3,om0c zpktdoform an experiment with a simple pendulum that is released from the horizontal position 8mt, )pdkvc+ 3oow0zg 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) po)r au8k8 2c7epy v8to k0shr28 v-blpmint-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation tbo28u88l-p k v2h87v) skcrae0yrp m 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 kg puck movtt. chfmr2 wi*1nq+*vofa 9)(xcdp r(ing in a circle of radius 0.5 m on a horizontal frictiofcr( xwi p+cfront*dvah m *tq21.(9)nless surface with a speed of 2.0 m/s?

  05.03: What is the centrit(, .c o ozfrjmow9b5q u93p:mpetal acceleration of an object (mass = 50 g) on the end omo(ou5orb3jtcq9.p wz :9 m,f f an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moveskznbm:)ek vpue:2-r ef2.a- g along a horizontal circular path of radius 0.8m with a constant kinetic enn-ez 2e2m :k.)bvafr e-k g:puergy 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 string and whirled in a hori+n 3)gfrpsh)j) bz2fwhe; qj lpl, 62fzontal circle at a constant speed of 6.0 m/s. See lw;6hs2)nbjf3hr) p jz 2 e l)fpg+,qffigure 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 18u7ufrc6hg*c5q4x deh 0xgn rope, in a uniform circular motion. Which of the following statement8uxrcgehufcd67 1q x04 *n hg5s is NOT true?

  00.19: An astronaut in an orbiting spa-6gkaa j4yquooh8jf74b 2a0t sgjiom /t7 8*zce 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 v, and the tension in the string is F. If the mass, radius, and sfj ouj oy/qtg *7 zs8obj-gh8ma ai27a6k4t40peed were all to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until4x rhf-ar6on,p ,f k8a,fu 3ec the 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. What is tef r3ukox8n ,-,fa4cpr a,hf6 he tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a roan4v-x t9plwc 2d in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms4 2 9t-vlpxwcn 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 constant9k kk/ z/nx dc4cx81g811ko0ibv ryf d 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 kc0g f8cndr zxokxk b94i y18/vd1 /k1best 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 constpp4bow,ir vaky h4 ;40t3 3kieant speed. The magnitude of the net forceieh04r 3t kp,;4w3kp o4ivyab on the sphere

  11.47: A simple pendulum of length Lhasa point mass M rewblvtund;bo58fi wd (2w70irp4,nn8 leased from 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 (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 (point2tfu 5rdb dv7liw48 n0niwb8pw,;( o n P)?

  16.32: A mass connected to a string forms a 8y jfofu:ckd - a8:tb s9jve16q 7;lrzsimple 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 8za7 -rfy9f o1j jlq6t d ;kvubcs:e8:the mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newt f y3.bbn6ak-/+1ejl mbid7n tons 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 happensi/ny 1 7ldnefabb-.j 6 tb+3km to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surfac; z6boeq xef2y: k7cktnft) t,(zg 8d8e, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibri ftkqg :8;6b7z(etd8)ey2ot n kfcx,zum 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 cons6r kfc,6dp)o.hi-pv ltant speed of 3.24 m/s in a vertically-o oc,idhl .6-v)6rpkfpriented circle 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) are ay 6ku/xxii g8:t reston a horizontal disk rotating at a coyi6/:8kx u gxinstant 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 connected to the end of string and moves about the st,yd ;0 jtii6kxring’s fixed end in a conica,ijdx 0i ;6kytl motion with a constant speed of 4.0 m/s. The string 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 inv6(mndnk 66f t uniform circular motion as shown in the figure. The string to which the mass is attached has a lengt6mk6ndf nt(6vh of L = 3.00 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 horizontal disx :senv/b12ikk’s center. The disk starts to rotate from rest about its cenke i2:/nxs1b vter 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 witbak/:6o9xz t9awhp -x6yaf :n h 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 from re69pz/x-x: oaf a6awbyn9:k thst 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, with inrg,q*0ug r,iue -lyv;itial speed 17.0-,ilrv0ygqru;* e,g u 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 a circle, starting at the top, with initiaow4 ap28dac)l l speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise 2 al)do8p4c wathrough 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 buc.9te7f19kf g 8in e oy5f2wzucket. The bucket 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 enough for the block to remain in place in the bucket. When the bucket is at k7 9w.e92gcu ff8tneyf5io1zan 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.