95.02: An object shown in the accompanying figure moves in uniform circular3:l /kp 2wba4xu dud2n motion. Which arrow best depicts the net force acting on the object at the instndp4a2 :x u2k dw3/ulbant shown?

  05.31: A child is belted intoktol s;ni 1.-qdov4 bc( gjuvqw zu1u-b8*9,t a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direzu .*kqtw-igl1v-1u(j;ocqbs8to n94 , vbud ction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path d(j aj6f,f hx2at constant speed in a counter- clockwise direction. Consider a time interval during which the particle,f2f(d6jax jh 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 cz3n-yjoc8 .d md az/jf+l+m u9onstant speed in a counter- n9u3d 8j/ yzdafmzmlo.c + -j+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 Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwir (g ro5qhd/d*m4xtl2se with constant speed around the vertical circle shown. Which arrow best indicates the direction of *2( r5trogd/m ldhx 4qthe object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the endud5ys/0 q0a 1xv yqzc4 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 twirli0yszxu y5dq 1/q04a vcng 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- b+di7p o zuv,st65aj as shown with the arrows in the figure. Which one of the following choices best describes the direction of the avera5tj, 7bazsd- o+vp6 iuge acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform l3whvn47j xj8 an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagram with lwj8nx3 v 74hj $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) point-like63o,zq f2ppq y object rests 2.0m from the center of a rough turntable as the turntable rotates.py6p qz q,23fo 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 is necessary to keep a )dsgp( xr9a 9s 1. 0 kg puck moving in a circle of radius 0.5 m on a hogrx ad99sp s)(rizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (r xktm7t*1qh4 b/uvx, mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a xbqvr/x t,m7*h4 tu 1ksecond?

  09.24: A point mass moves along a horizontal circular path of rad,cj( h+ yrb e,kepo6fi2r2a 5wius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting onkpj6ywr(+o, e2ci h , 2far5eb the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 4:sr p3xutzh ,g ct5e+0.80 m string and whirled in a horizontal circle at a constant speed o5 zt,4g r:+s3xuthpc ef 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 e9z1+d 9.ifeca b zoro-nd of a rope, in a uniform circular motion. Which of the following statee.c f-9ir1oo zb+ d9zaments is NOT true?

  00.19: An astronaut in an orbit w8hho6k *ap7ding space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of the 7w h86paokhd*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 the string 70q1iqba pf5lpn k3y,c 5klr- of length L to which it is attached makes a 90- degree angle with the vertical. The mass is releasp-lbk5ynq0 k1cq 7priaf3 l,5 ed 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 ter.yt5j .ysj gl5ui i1v1rain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. Thg1s1l..jyytu ii5 vj5e 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 vjzc5r ;q. w:mr6xo wg*ery 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 followi. jx;qcorrw *mgw:z65 ng 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. Thens ,d(iuj5h *e magnitude of the net force,dnj(*e iuh5 s on the sphere

  11.47: A simple pendulum of leng je rj+4p,wob*th Lhasa point mass M released 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 magnitudeer +w*4pjb j,o 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 ma-m)ck rsj 7;tsss is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the tensimks;c - rt7s)jon in the 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 newtons is applied to a rubber sto afdcrmpru:8s q5f(0+pper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, (ru 0q5m8c: +rfa pfdswhat happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surfasgjz5- a(oo z h5z24auce, 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 j4 (zoz 5hao-ug5sza 2to 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 constant speed of 3.24 4ib9 5xqaobxti iq.t6 usjaq;y(, zz. m3xn;* m/s in a vertically-oriented circle of radius 0.75 m. What is the net f94q;ya xmt6 to3i .nz .(5u ;bbiq,ixjzsxqa*orce acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at rea4 ;ysj5+4eayrj j6 b7p*n yvlston a horizontal disk rotating at 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 i6+4; vare n7pyyl5bsja 4j*yjs 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 moves8 kpybseqy/g8f ;r1 )la+fp6g about the string’s fixed end in pg+8ryfbgelf8qkya ;)6/ p s1a 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 $θ$ 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 qceqb;z; ikg,m5 rp2*z /bzg,4h3rslthe figure. The string to which the mass is attached has a length of2pc5 3z mqi,lzr g; rb,gs;h*zqeb4/k 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 v9tu)8x. qdak.0 cm from a horizontal disk’s center. The dis.v) t9akqd8u xk 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 wirl4ix3v-bc .y3 xhr xfk.h.+lth 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 svx.-hrc b fixlk4x3r.+y.3 lhtarts rotating 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 moves in a circle, starting at the top, with initial speed 17.:no) 5xr: rvwd0 m/s. The object’s speed increases uniform5v: downx):rr ly 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 spe,86il1poo1- n 3f r7.xw bvz6cmrxbdyed 17.0 m/s. The object’s speedlvrfix ro17pbz md13x bn o-8.,wc66y 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 bottom of a bucketlbg*g5su ml .xk xxpr6,(ja 0ae47gl2. The bucket is spun in lxg2mbxs5gl,p4.g x ak j7*ual06e (ra 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 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.