95.02: An object shown in the accompanying figure moves in uniform circular m-w qfk0 ;,,h7tbwd4ov l jorh+z od58votion. Which arrow best depicts the net force acting on the object at the instantvdo ,8ql7dw4 vb rhz wtofoh;5k- j,+0 shown?

  05.31: A child is be jk2 u4+-chdi.-axv*t rw:ueulted into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the - *+tuvieu d hwj-.x4a:u krc2 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 rwp tw:/j)6v pkq 9v3 k4o. ucsd4fy-da circular path at constant speed in a counter- clockwise direction. Consider a t qp y4rs.w dvop34djkk u:twv )c96f-/ime 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 circuld)lcun0y :e6rcg nj5j 2j2 roe3,hzt4 ar path at constant speed in a counter- clockwise direction. Consider a time interval during whi64h5n y0r geo3c2,u:dlnjjjc e 2r t)zch 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 /89nya mdqkazfd+x;g f ::a6jvertical circle shown. Which arrow best indicates the direction of the object’s instantaqgk n 9mj d8yzda/;a:6+ axff:neous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of zt-2u1a;x tzna 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 labeled P in the figure, at w-1uzn2a x t;zthich lettered point on the path should she let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped path as shown q4tf:2v(zm bk with the arrows in the figure. Which one of the following choices best describes the direction of tmq: vkft2z(4bhe average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum that rw4o(07g juu zis released from the horizontauju( gow74 zr0l 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 frou,)8p8-oxhs vc8 gecvm the center 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 is 0.80. What is the magnitude of the force of friction acting on c8vgx-8)ce v,uoh ps8 the object?

  07.19: What net force zg7xdyi a,ul vn9;)5j rn7 q1tis necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/l;urqj91)7digv n atny7, x5z s?

  05.03: What is the centripetal acceleration of an o ;pr4kj3d;ae6s1b l oplrz25ybject (mass = 50 g) on the end of an 80-cm str3zkl r2jpr;6s 5ybd4eop;1l a ing rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizonhzfk-ko m-6. l4d,weg . eel,ntal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of thedk ,e,ehnk6lez.l-o4- wgfm. 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 whir 2d)l14ngs g,oxew*mm led in a horizontal circle at a constant speed of 6.0 m/s. See figure ed m4l ow1,sgmx2*) ngto 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 uniform circular motionbnoyc mg h1fpdh1(yw::.a*l: rz4f l 4. Which of the followyfcl4h y: 1rhd1g.pnmo:b (*4: wafz ling statements is NOT true?

  00.19: An astronaut in an orbiting space craft a x5fjee s+(/( cdzuq* /(muh(zuq9g odttaches 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, radius, and speed were all to du+d*(f9 dej/m((eh u sc5gu( q/qz oxzouble the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the stringb vttm0h9x, )i of length L to which it is attached makes a 90- degree angle )9tmbx,thv 0i 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 through the bottom ofthe arc?

  94.15: A car is traveling rq:eyo41k 347xkfrh u 1fcf3r on a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curv34o:f ru11qk 4c7 yxr 3ferhkfature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 mh fq.v8e u*z7qn)1sg6f9+ oud -ufc kd/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 upwvkudqu n1e7gcqs 6).h f-9+z uo*f8fdard force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical ci+*kau3zl yg 707 deqezatv04tkm+m9g rcle at constant speed. The magnitude of the net force ol * atmzd av7 +4mzuk9tyg0gqke0+ 73en the sphere

  11.47: A simple pendulum of length Lhasa point mass M vi.ka se+;r +szii;2jreleased 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 (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 isk;;i+a s zev+i r.2j(point P)?

  16.32: A mass connected to a string forms a simpl8ds6e tr+(*4x qdpc idaf1.zde pendulum. The mass is released from rest and undergoes simpte1.(+ dar 6ci xf q4pz8dd*dsle harmonic motion. Which one of the following 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 appliedr mew rpvbdkk 5*42t8( to a rubber stopper moving at a constant speed vdk 2wr5 8rbtep4*(m kin 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 frictionless surfapl*1q bbng 18; uq7-z2xq cwhfce, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from 7*l- zcb gh8pqx ;2bfuq11qw nequilibrium 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 a 4.0 u7zo gsy1m;3 rkg mass with a constant speed of 3.24 m/s in a vertically-orien sougz31y;r 7mted circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identij) +qet zasu bg0x 9gvrna-m 2s8+4z+qcal coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of s4n-g qz x+0abumaz q92grj+v s)t8e+ 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 tozu9qc4 qs,u o61p*xx k ,a8dse the end of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. 4ax*eszu,s9 8cq,ku6opqxd 1The 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 circular moti)hsv l:xvaq6s)lyg (m/d, ( cion as shown in the figure. The string to which the mass is attached has a length o6glli:/ x(a ,dhvs)vqs )m( ycf 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 x0r9,aoe80px pnrsi5,gq o x )a horizontal disk’s center. The disk star a 85iogx,pn,q9x rpx ero00s)ts to rotate 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 M = 2.0 kg is attached a distance R =1.75 m f3p ui be1ouf;9rom the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant a 1oufu ep3b;9ingular 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 sc q bv8+px j*og5*wg: w17liwepeed 17.0 m/s. The object’s speed increases uniformly until it has move ovi:wc p5*wj gx+gl*ebw q178d 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 circl n anl0fcysm)y*xzw8rr4n 0u8h5/6i xe, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclhu 4)nrs n8c5fzwyx0mn8 yr la6*ix0 /ockwise 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 bucke pgp(:g.abw/e t 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 in place in the bucket. When the bua.:gpe/(bw pg cket 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.