95.02: An object shown i.hwp+baj;4.a0 qda oen the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant shown? dawe.ao0p+b h; q4aj.

  05.31: A child is belted into a Ferris Wheec/cro+ ;- opdxci.qz( l seat that rotates counterclockwise at consc-+rqoc ;.pc/o dzi (xtant speed at an amusement 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 continuvmylii syy f+h5+n+9 -ously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle y9n 5mh-i+sfv+ i+lyymoves 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 continuo(4 d k5b wykr4q7y/bobusly 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 the circle from Point5b b4yw7b4 yrdoq (/kk P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves cloj 4xe 4cygu9)3(r:pf somk*dgckwise with constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’s ifo*4mkusj)gy(c x4 39e:d r gpnstantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string countercloexx taz7):x u/ckwise 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 in 7)a extz:uxx /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 as ji)5r:dznu:g f/wb 8gshown with the arrows in the figure. Which one of the following choices5dnuggzifbwr:8j: )/ best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simxjy4wnky -w6h- .3ksodkb e9di2/ 4 zgple pendulum that is released from the horizontal position at rest. At thgs9hdw dj4z 2 kkyyn. o4kiw6 x-3/eb-e 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 a5hinv,q4 ka*q;ixn 2b r4v9tz rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 seconds. The coefficient of kineticb xqita,v2;49 zkn *vihn5q4r 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 j+yvy/py 82liis necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontaljyliv2p +y /8y frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on the en)-cn jr+tq9ftd of an 80-cm string rotating at a constant rate of 4 times a 9tt)+cf-nr qjsecond?

  09.24: A point mass moves along a horizontal circular path of radi4ixr:s8snk-t 7ofkw ) us 0.8m with a constant kinetic energy of 128J. What is the ma 4sk) noikw-sx trf:87gnitude 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 horizont ks9,(, w o/to okzfuwpskie.)i d)0z4al circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball duri 9k tk.zwzdf,,ip )(wokeo )4s0uso/ ing each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a unif.a gcc:nr/m v+orm circular motion. Which of the following stc+:cva/ng.rm atements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a /wgsxt n1u1.)fv92 xv0uxl tk string and whirls it around in uniform circular motion. The radius of the circle x)2u0tsxxn9 v .k fl1 /uwtvg1is 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 the zcf/loj22 xd2m9hy n- e3sa5bstring of length L to which it is attached makes a 90- degree angle witmd5 2/ nxjo 92 lc3ze2ybsfha-h 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 the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, sem67nfho)1 azv e figure to the right. Assume the n1vho 6az 7f)mcar 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 moves over a hill at d 5xir ux*u z*o-i9-6dn1tzkr y)7jf ya constant speed of 12.0 m/s. At the very top rf z dd*ix75z -u1kny9r y-o6xit)j*uof 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 car?

  97.13: A small sphere is moving in a vertical circle at constantiegd9 z*-z ej8 speed. The magnitude ogjee*z-i9z d8 f the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest frtgtvn8s*8f ) nv5: imkom 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 stn)5 nk8smv*vigf8 t:tring 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 releaqk:w.eah yzlc 4/)o;ased 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 the mass (F) when the mass swing; c .z aq:o/kae4lwy)hs through its lowest point?

  04.41: A centripetal force of 5.0 newtons is appr)y ahe8k8dp je,t )j(lied to a rubber stopper moving at a constant speed in a horizontal cir8eyjd rep,8)()jat khcle. If the same force is applied, but 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 ))zu * b9l1yyss q6eexrest 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 locatioq)l1* ) yeyuze69sbsxn 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 mas( m q5.j4.jsc4drrtua s 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 mass when it is at the lowest point of the circl sr.4tduja jq cr.4(m5e?

  14.23:Two small identicalaee7y; b(/ udef4tag: coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of au7b fd:eegta(y e;/4 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 thn jty.:hus;+ oe end of string and moves about the string’s fixed end in a conical motion with a co:; .yjtnoshu+nstant 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 in uniform circular motion as shown,lhr7 wq-wa4x:u2tbvk*0u r x in the figure. The string to which the mass is attached has a la 7 w*q:rhluxtub4-2, wkrxv 0ength 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 30byng0, gr5rm m3)opcv (ba*g5.0 cm from a horizontal disk’s center. The disk starts to r0rgor,v b gap(cgn) 3 m5*by5motate 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 attached a distance R =1.75 m frome ( pn,nrq ui62;jr kd0c4ggm. the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant angular ad 6(c0j,ie2pu n n4;kg mrqrg.cceleration $α =5.00 rad/s^{2}$ 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 th*k9/z jri:w9 c3k wl6b mgr)ra 4izd;we top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has4i lk9wzj9*brr/gzrw3 k;6i dcwa)m: 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 atrw: k3ixni y(20ir8ov the top, with initial speed 17.0 m/s. The oi 0rik(2n3 :vwyo8xr ibject’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 time for this motion?

  17.38: A small 2.0 kg block rests at the bottor+;a2ae fbr+zytts:t1 :l+ g cm of a bucket. 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 jusyg r:tttl;b 12zascf ar:++e+t 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.