95.02: An object shown in the accompanying figure moualocqpv1(m7k (0h u d im+a0(ves in uniform circular motion. Which arrow best depicts the net force acting on the ob7vm0 pu 1 o(u((m+caaqdhi0 klject at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates *r3hqyz2h q6 h74h5h n sfzh9ini4ni8counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerteszfn4 ihhry* 7h29 qin nhhh84iq356zd on the child by the seat and belt?

  08.14: A particle continuj iaz (mke+h/8sf9iq+f+t*wzously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time+z(fm8a+j qiwe/ h+t9ik sz f* 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 pps)(7 4fohi ehath 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-ws (f7 op)eh4hiay 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 consta.,w k9q*hl jwg 7vtck3nt speed around the vertical circle shown. Which arrow best indicates the direction of the object’sgwwv,kh73ckq l *9t .j instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the enxs)hjnry( exuh4deu* ss,-ldl 4 7h+8d of a string counterclockwise in a hoeldshs (l)+4hu7,e uh8j ys *-dx rn4xrizontal 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 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-shaa+(0-okd 8gbw2jkzqw ped path as shown wi-oq 8b(gwj kzakw d+20th the arrows in the 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 perform an experiment with a simple pendgk9 c7/hk0i cuulum that is released from the horizontcck7 igh/90kual 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 kdjo46 j*lv1o9s1 ic 2uj*mgxrg) point-like object rests 2.0m from the center of a rough turntable as the turntable o jg dvoj24c*ulxr *1js9i61mrotates. 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 tovai )33 upsmy- keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless 3s)i3a-yum vp surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object ( wk77oxu u2a.tmass = 50 g) on the end of an 80-cm string rotating at a constant ra.kox27 7wuutate of 4 times a second?

  09.24: A point mass moves along a horizo*sf-wvt.t 73eryw73 qi6 0kmf,abwz cntal circular path of radius 0.8m with a constant kw60.ek-ib 3ct7z qvfsww*ty 7,m3f ra inetic energy 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 stz )rflznvs*-k : a-enhc:yc9mh 6t(r.ring and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution -6*.:s-azh:n y(kczr) ml rhv cne9tf is:

  99.22: A child whirls a ball at d )cu e0mmuo: o2jk*5uthe end of a rope, in a uniform circular motion. Which of the follow u5u2m ecmuo:)*0 jdkoing statements is NOT true?

  00.19: An astronaut in an orbiting spa 4bjmynp,3 7oj ;g4 3hlwsery)ui id6*ce 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, ru;4p4onim, jd3y 3jhr7sye w6b*gi)ladius, 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 strp;5 (repw /gf;gw ;ruapc2 ;fbing 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. Ww5 fbfec;wp/(rrp ; a2u;pg;g hat 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, see figure to t 6q4b4ph4b3:nim +xa xi dp.lthe right. Assume the car 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 we.hlm 4n a 4+b6xbtq34p :pixdiightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s06w1x1vymj-nt s n1 v)q,iir p. At the very top of the hill, the shape of the road can be approximated as a circle witj, nr)-w sq1vpn0y1i6m 1xi tvh 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 constant speed. Thekrgg2i/z;y5h8ds+f s m cnx2u)0+ qei magnitus2gqxd/eh; s5f0nui)yc8z ig 2mr+k +de of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M relh3tzp5v p.xz9:,a sfhi6n+ jneased 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 thnpz6 z f35th.nx +,hsi9jpa:ve 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 pendulum. The mass :n18epimr s,e 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 for 8emisr ,n:p1ece 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 5ujpopt a+;bf2j+u-(prgy5 ,6 qjk.ku.0 newtons is applied to a rubber stopper moving at a c+t+ukp,5o6ufb kp2ay; q(-jj. r pgj uonstant speed in a horizontal circle. 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 rest on a tp ;5xj1kmb 8wfrictionless surface, connected to an ideal horizontal spring th;wtmbj5k 18 pxat 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 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 ,24gxik u.ah,m omkh*a 4.0 kg mass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force act 4m,ih,u .kmao*h2 gkxing on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) arj :0w:3.8nzhz37bdgklm zvce e at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through itb z:egznc8h d30:kj7 mv l.wz3s 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 a rkgv-szc ectp.xv 1p(y9z 172bout the string’eskpz17c(zg2x91t. vcpv r y -s fixed end in a 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 cis9h3bn,:0ncl8qe3y8 tb 7siz3tim farcular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m abnm 3sftsn08 eqiy8tzh,7b i: 93alc3nd 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 restn /cb1)j p n;hq3zx2ah 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with 3x jqpn1 bhnac2h)z;/ 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 frsoim(pxk 4m4 2coi)1mom the fixi o)42cmko mm px1s4i(ed center of a disk as shown in the figure. The disk starts 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 dnam .: caf4ct5( 6shw17.0 m/s. The objfs5a c.4( hna:dcw6 tmect’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 ikr+h(3lx o9qonitial speed 17.0 m/s. The object’s speed in3o+kr(9xq ho lcreases 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 ty-u yi(2*fh wat the bottom of a bucket. The bucket is spun in a vertical circle of radif*wuy( -yt2ihus 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.