95.02: An object shown in the accompanying figure moves in uniformd1 hkr,0e p,c3);uwvbn a5oyjxc z/;y circular motion. Which arrow best depicts the net )w;cby;p0cn, d5jav3e uyzk,/ ox1rh force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel sgv bx)cb8v/eav.g vo, v)+ a)oeat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerte8e)v/o.cv) b+gbog xa v)vva,d on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constm iw i guzq8t7*f fnh7.m584kfant speed in a counter- clockwise direction. Consider a time interval during whu78z5.ifm8hkngwmt4f 7 *fi q ich 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 continuousl,p+remo5r0h w y moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which therorm5+, ephw0 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 clockwis-+ wsup3s se t7c76khoe with constant speed around the vertical circle shosp3ck w-+7ou67 esh stwn. Which arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls ap8n2 vl3g1hlcgh3;dw0la3 snb( l3o a small mass connected to the end of a string counterclockw o h3clgwv(a ab38d 10pn;hg3 l2sll3nise 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 the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves wito7/kh qa7e dw0cf2wq4h constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the dire wqaeow72 4h k/df7cq0ction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum tha19/stq djbk5 wp-g)gc t is released from the horizontal positisqj-/t)dbp1k 9 cgg5 won 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 from the center of a 0kiy2.naw )f8q73 r,pb rdvflrough turntable as the turntable rotates. 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 thevn 2,kirp 3bwl7 fq0r.fad)y8 object?

  07.19: What net force is necessary to keep a 1. 0 kg puck mo;kjmb*xo;h qpm. d8u1ving in a circle of radius 0.5 m on a horizontal j ubm1k pom hq*.d;8;xfrictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) onlat7 a2uplvf(s u k,30.wm/yw the end of an 80-cm string rotating at a constant rate of 4 times au2 wm p lu l07vfs(,aw3yk./ta second?

  09.24: A point mass moves along a horizontal circular path es a28+h5olhm of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mase58sha ml2oh +s as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whpbjm jvo k7o7vi 54p,4irled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the b4m kvpjo,4 b7p7o5vj iall during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circular mopdq.wp,/:xas dk( 4 +fbxwc:y*z rs9ttion. Which of the following stateme.atdrfdy b/*p4zxswkx9 +c q( s,p:w:nts is NOT true?

  00.19: An astronaut in an orbiting sp11n kb y;vi-m+b t8algace 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 t nvbg; i8+byk1- atlm1he 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 of length L twmxj9o /uhpww j rm8y-3x:+x :o which it is attached makes a 90- degree angle with the vertical. The::-x98wx y x+urh/ 3 wpomjwjm 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 hiuoe7;bg ig *cehy-o*gp5 6*z llly terrain, see figure to the right. Ab6*;ice*o o7-g guh*lzy5pg essume 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 weightless:

  17.10: A 2000 kg carf iwz spvdqa(s, n9y5va-q, 2n3hi;5m moves over a hill at a constant speed of 12.0 m/s. At the very top of the hill, thfna,,(pqmh2 3 qi d- 5vnyasi5s;vwz9 e 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 movs pmto2((;4nm 6ey rcqing in a vertical circle at constant speed. The magnitude of the net force on tsm(m4 q2;(cet rp6noyhe sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest f0c m*sxuz x;:e;8nxunrom 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. e;8c;ux u*nx0nzm: sxWhich 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 h)v:sfl+iu2g . The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly r+sf:l i)uh2gvanks 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 applied to a rubber stoppvk 66en;pvvcq2i5yp4 er moving at a constant speed in a horizontal circle. If the same f2qv v5;6i6kypev4pc norce 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 frictionless sur+ ;wzi2/ fxwvgface, 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 ext/2f i+gzv;xwwended 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 xhhjgs) iw-d+rl/zm2 )w m-o93.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it izl-mgr )jxi hw+ 92 )wmhdo/s-s at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizon5p;r jb, 2y:uuit 4mxhtal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance 2, h:bmx5 u;pyuri jt4of 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 aboutkqsm vsmto)9bsb- 7, 4 the string’s fixed end in a conical motion with a constant speed of obbv qs-k7) ,smt94ms 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 h:v)4oahvq7c uniform circular motion as shown in the figure. The string to which the mass is attached has a l4)h cqvh:7v aoength 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 is3n358j1dj svijh n5 wq at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular a8vjh 5w3 n1jjsiq d35ncceleration 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 ma.eier 47h9 w: uyu(edfss M = 2.0 kg is attached a distance R =1.75 m from the fixed center of afuwy4e (9d.ue e:7hi r 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, startin1oy.r1;1xv8dfz tlp- dvtg0dg at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle rdl1 1vzfdgt-yv p0;8d .xt 1oof$55^{\circ}$. 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, start 4jfb8wy2 fuu1ing at the top, with initial speed 17.0 m/s. Tu f42bf8u1jwyhe 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 time for this motion?

  17.38: A small 2.0 kg block rests at the bottom of a bucket. The bucket is spun c3 is-ff*b jhhqb2:q*in a vertical circle of radius L by a rope. When the bucket reache hqqi* c-jf*bb:3f2shs 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.