95.02: An object shown in the accompanying figure moves in uniform circulojiu3o j r0f.a(s;r, iar motion. Which arrow best depicts the njfr0; r,o oa3s ij.(iuet force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterc22(muofophzq 5t7ux8 lockwise at constant spt7quf2poz8o(h2u5 mx eed 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 continuously moves in q(c taw*w0g r)99yeyga 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-w9ygg(wy)taw qec90* r ay 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 p4ny ,dl2bm8irath at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from py ,8d2mbinl4roint 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 constanm0g yfm 7a*2wjg; i9mct speed around the vertical circle shown. Which arrow best indicates the direct9mmjf gm 0w c*72gay;iion of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass mnk5 ,:ymr7xh 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 7 m5:xkrhmny,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-shapem rbso lo3r wo:+k)6a rvx,1u0d path as shown with the arrows in the figure. Which one of the following choices best describes the direvoolb0ox)r k 6 r1aw: sm,3+urction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an expw *2t.wzpgd l)eriment with a simple pendulum that is released from the horizontal positgzp)wt .2*wld ion 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 roughl :xr-:l,hwtl q5 qcq2 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 i:c t-lllx, qq :25qrhws 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 necegfv t;mr4+fchn9 2o 7qssary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizoc f rg9nv7mof +h2q;t4ntal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on;. ft-,wuky0beu a8mv the end of an 80-cm string rotating at a constant rate of 4 times a secv f.t,eu uy;0bk8w- maond?

  09.24: A point mass moves along a hor)9lg ,(mvh vu5fwm 4nyizontal circular path of radius 0.8m with a constantwl9,m)vyfn(mhv 5 4gu kinetic 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 h bs:et z3h0zqqzaoj69 u-)1.e*t dct m string and whirled in a horizontal circle-)9zcb qh3o e.:atq1zdtu6*th szej0 at a constant speed of 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 end of a rope, in a 4/iwc1 :qrmwmuniform circular motion. Which of the following statements is NOT true?c 4q:1mwmiwr /

  00.19: An astronaut in an orbiting space craft attaches a mass m to a striir :ungnq-e8/ch6 g:ing 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 d8rihi -ungc:en/ :q 6gouble the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the c 0ad372qo33 r 6 xfhv0dcj ofq9geyp3string 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 tension in the string when the mass swings thr3dd6x27vc 3 0y qf0fa oejrhc93oq3pgough the bottom ofthe arc?

  94.15: A car is traveling k ;8i;vmxn0 cnu82ewm on a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bm2nm;ek 0 uxvni8 8;cwottoms 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: ;aw6ko fov9,qc.9 sw fff*lx hill at a constant 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 best represents the magnitude of the upward force exerted by thew.qlkf , a9:ox;off6 wscvf*9 road on the car?

  97.13: A small sphere is moving in a vertil ,f*3 e9*qojtfo;gl zcal circle at constant speed. The magnitulfq3*;lgt9ef o, ozj*de of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M rele1o +q3qtm3lyd sdh6q+ased from rest from the horizontal position shown. In the absence of air resistance and f3 6qqyomsd 1dql+th+3riction, 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. 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. z m8.rr6t -(9t, xhs+rxqhmfaThe mass 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 gravitatt( sr a xxm6r.m-zr9qh+,fht 8ional 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 stopper moenx ltwj)fzr* *l+z.: ving at a constant speed in a ht *zxfr)l:n *lezj.+worizontal 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 frictionless surface, connected7fgcfl*s.guebw. wb5r97 o f:/ nntd4 to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds cftflfw*d wuno:4gbr 5/se .n 77 .9bgit 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 a 4.0k/ gl p5(h42;eme debv kg mass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What isbhv(p;e4 eedkg l5/2m the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins40 x vdbm (fzhx,g/.o6mc g1ml (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular tbm c0f gm.4o1/6xdlh,mv z( xgo 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 378ym) si 6zim *njf+oorbl2hto the end of string and moves about the string’s fixed end in a conical m+ f2)zisjm68broi7*nhy 3 olm otion 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 *xqh ;on mted8gr s.:mqh7b; 0in uniform circular motion as shown in the figure. The string to which the mass is attached has a lengthhnq; em x g:8moq*;db .sh7rt0 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 30.0 cm from a horizonta 9 8wwzwcifx ne-qy./ w8anx+-l disk’s center. The disk starts to rotate from rest about its center with a cona.wf-/cqwnzw +9wx88y i-n xestant 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 ma, i ialz-6b*ktss M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown i-zl6 t*ik,abin 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 initiart /evbw gf7a)+*7c/;pnidp wl speed 17.0 m/s. The object’s speed increases uniformly until it has moved e 7vt wbcdw/;+ )i p/rgn7ap*fcounterclockwise 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 geucf68b9 kqk /-hlgve)7a8wthe top, with initial speed 17.0 mu/geahqk8bvwkc 7f9)-g6 8 le/s. The 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 bucke; jli-f8*v )lbrs4urt t. 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 just fast enough for the block t)fsl -* 4;l8bur jitrvo 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.