95.02: An object shown in the accompanying figure mo6 z h,o ivygpj*02+osvves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant , opyvo 6 jv0sih*z+g2shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockpt1 s,5psfx+ vum3k j,wise at constant speed at an amusement park. At the location shown, which direction best representsm s,3jp,5uk+1tp vsf x the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a cs 4 q1del+s/ocw3l2t,f4h lcx ircular path at constant speed in a counter- clockwise direction. Consider a time h 3qwlsot41s, l4 d2x+lfcec/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 1q :q eg5qrc 1uibe-wkz 7xf,mffz+6-ewwm-: at constant speed in a counter- clockwise direction. Consider a time interval during which the pac6zewk :1w:b1, mme-gfi 7qw-uxq- f+ezq5r f rticle 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 clockwise with constant speed aroundpwe eq3;v00a2moyqm)c,j l v3 ,3m+esaz- tkm the vertical circle shown. Which m0ys-) zm c0+ a oq3l3,mv, 3; m2pavjwqetekearrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a sm ws rbcoi)77mo k0z)2call mass connected 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 la rbo i)7k2c0z)o 7scmwbeled 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 horsji.rx m7d8jf e ptj:vf8l1k-1eshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling fd8l1jt r78m. :ivf1j-jxpk ferom Wto X?

  08.35: Astronauts on t5 mtohi q:p-4,f dkp:xhe Moon perform an experiment with a simple pendulum that is released :dkh 4txpim-p oqf, 5:from the horizontal position 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) point-like object rests 2.0m uv2./7o++z vs 2 cfi n)crrrl kkb/zu.from the center of a rough turntable as the turntable rotates. The period of the tcvb. 22 vk or+/unsr+7zzc/u) l.frkiurntable'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 1. 0 kg puck moving 14 o(w5dkemzm6 swqf6xkz4i ,bs* w5iin a circle of radius 0ws5mz(dswk, iqzo m*6x5 w4b 6ike41f.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an ob1n6/ax :7t onl(qe;gzw 6hkjkject (mass = 50 g) on the end of an 80-cm string rotating (a 6tl k :j/;nhqw7ox6ezkgn1at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular h yl 69 jv++ck6q7feng o3do0pv+co /spath of radius 0.8m with a constant kinetic energy of 128J. Wha ol/n63qg +s +oj k+pv7cf6e9ohd0yc vt 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 mmumiw y3 /,5qp string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done uym 5 /3wqm,ipon the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in akx/j: toahaxym1k4)rr67lw/ uniform circular motion. Which of th 7karjm )/:aywh1x x 6kto4rl/e following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a sn8o;g pc*c-:dg7xwh8 m-z sk(zk i6oitring 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 speed were all to double the te*6 ;8z pi7:sw nic- -odg8oz kx(ghmkcnsion required to maintain uniform circular motion would be

  07.22: A mass m is pulled outwar/ ;lf vpg9ny2 i8bu)oyd until 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 the g) /yy buif;p2no 8v9ltension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hdx3cx; bype+ (illy terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have ra xp3( xbceyd+;dius 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 cdlju2*(vrz7 yogu ppg1 0 vc7w +:a/zdonstant 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 bestc 7gopdl pvwu7jy+ua *2gr( 10zz:d v/ represents the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is mov5 j,4hwdg 3blving in a vertical circle at constant speed. The magnitude o,lhd5 b gvjw43f the net force on the sphere

  11.47: A simple pendulum of lengw4 jws5 7nkcapgc*hskl)j5 15th 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 magnitude of the force from the string on the mass (tension514a5*psj)5w gcskkcljnw 7 h ), 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 siy30jbh30ltxnp/sn83jvf ad 8mple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following y x0nhpv8s/3 fj 3 n03abdtj8l 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 swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applpf6/;r2 mwl qoe/k4lx (szh6vied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force l;f6e 2q w/hmspl4or v /k6x(zis 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 at9p l8/daz(-ic0e y pib rest 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 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 yia8d-zp e bi/9 (pc0lback 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 wp. y r4ptn6n7pith 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 isn4ptnr py7p.6 at the lowest point of the circle?

  14.23:Two small identic6z xry3ciakct( c40 (cal coins (labeled X andY) are at reston a horizontal disk rotating at a 04yzk6caxc(r itc(3 cconstant 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 abou+q1qo, m z)cwpt the string’s fixed end in a conic1z cwq m+),opqal 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 g:ksy(y jgdv.s7,3j 6 .t 3rkunbfs.h is in uniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle yj.6gv7hnrgy(fksu..jks 33td, b: sof $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 1di7j r-7p9u(leyc3qh 1.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rot77leuprycj q39h- d(iate 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 995h ggg0hfz dM = 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 rota909ggzg5dhf h ting 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 7rsga 7ch uez1,y1ht(.7aths slv ).pin a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases z u s1ht,ap esvy7ht.a.)r1l77cgs( h 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 initial speed 1rfkw :i/ p0q3v7.0 m/s. The object’s speed increases uniformly until it has moved counterclockwi0 :/kf3pirqwvse 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 h174k zqfar.g in a vertical circle of radius L by a ro a1k7f z.4hgrqpe. 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.