95.02: An object shown in the accompanying fin,* cwev63o g:ahjq i*gure moves in uniform circular motion. Which arrow best dep6wh *qga3nji: o*cve ,icts the net force acting on the object at the instant shown?

  05.31: A child is belted into jac 7q8w wo)8x;m(zgya Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At ao7;w)wqmg (8xc yjz8the 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 t6d1x ye ux:5ua 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-way around theu x61y5:uxedt circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously move/ yg ggvryrdkf52 b7i* ,;vx6ys in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during xydv6rgf72 gg5bkr/ *iy;y, v 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 clockwise with constant speed around the vertical ca 0hb(ripz ,:r9 2wj -mtxl:iwircle shown. Which arrow best indicates tw,wbjat:z ir 02pmx9l (hir -:he direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the enpieozd.+( 1vwd of a string counterclockwise in a horizontal circle above her h oizwp.e(d+1 vead. 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 constantfy q b,/2t0lb hew(*mi1dbc5n speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of tm5c qt/2(nlbb,yfihb 10we* d he average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum ayw1dwm-g n7a(wwpwr93s/ s1 that is released from the horizontal position at rest. At the moment shown in the diagram with (p1 7ww9y3s/wga dw-wrsnma1 $0^{\circ} < \theta < 90^{\circ}$ , 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 cdcc-kn5t - lpb0s**bjfys80 q b9ppe+ enter of a rough 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 tp b kqsd*5fb p0j*cn+8c-s9-pb 0ely 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 in a circeg7 -vrv:vx2c cojb)48u 2xk mle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0)om- :8e c7 x42 bgk2uvrvvxjc m/s?

  05.03: What is the ce.qtw ,o 8p16sjo:qwsantripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate tw ,6jsa8o wopq .sq:1of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0. cm1pxp)4b r8sk hi8dz/it9oe0z 8tn88m with a constm / rb88ckz4)pdoie1i tsnh0z p t889xant 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 m string and whirled in a ho. e ,-c7chqohdrizontal circle at a constant speed of 6 dhc.o, heq-7c.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 unifo-i4e9 d dof2lqo,+5 fg5c:ltkbdh 4x zrm circular motion. Which of the following statementol5e lhckd:4idf, b4otg2-f +z9q5dxs is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a qhztbn h 7u-92string and whirls it around in uniform circular motion. The radius of the circle is r, the speed of thhzu - bq9t27hne 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 pulbu5 c*e tvz b0h8(pz/zled outward until the string of length L to which it is attached makes a 90- degree angle with the vertuh* bzze/c (5b 8zp0tvical. The 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 hilly terrain, see figure to the +q);ughr 37qespl yo; 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;sqhe ur7;o 3py +glq) feel weightless:

  17.10: A 2000 kg car moves over a hill at a constantw+ x2tv;rmq8i 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 magn;w+ x t2qvi8mritude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle uxtqh 5,(ek3nat constant speed. The magnitude of the net force oh 3kux (nq5e,tn the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from resti u-keq5-t* i7aj 39cbn 4krnb from the horizontal position shown. In the absence of air resistab9 in 4c rkau5tq-ieb-*j37nk nce 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. 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 penc)8megeel 2gar(3 j t(dulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the follo2m jaet)8lree(3c gg(wing 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 fu2 u9 rx .:galtocne6/orce of 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happens to the speed onta u/29g.cu x r6el:v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a fricttitap me gg)1mx- .a56ionless 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 back x-pi)atat1 .mge5 6gm30 cm from equilibrium, what is the necessary force applied by the person to hold the mass stationary there?

  12.22: A girl swings tim;vis+n+7t 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 acting on the mass when it is at the lowe+titv ;smn +i7st point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston al5qbn xy1 qq49 horizontal disk rotating at a constant rate about an4q5qnq y19 blx 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.ag-+ ov eqhd4 moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has av gehdoq-+4 .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 unifo8*bbq7kj z10o29kl3w aqtu hhrm circular motion as shown in the figure. The string to which the mass is attached has a hqzwl*kbq j87tau h 19k3 2b0olength 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 2* qbk-lj+:rw tb kun2at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular accbt2 krlnw qk2+b*ju-:eleration 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 mwo,8od.o :t 7or/suif from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant angular acceleration/o:iw o7dtf,ro. o8 us $α =5.00 rad/s^{2}$ 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 )1ksu bc; . 3kw2wl :aquxripnu6;en7circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moc)s k6 npbi2lx rkaw:nq;;31uw.ueu7ved 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,wpr-4c.h/,t wol )qndy .e ig- with initial speed 17.0 m/s. The object’s spewgyhe,q / cnpi )w dtl-.-4o.red 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 o6/ + xreegza1jf a bucket. 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 to remain +x6aejz r/e g1in 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.