95.02: An object shown in the accompanying fi2j* s;w;nrhufgure moves in uniform circular motion. Which arrow best depicts the net force act2f;s ;*hnru wjing on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat 96 xiysg3n: gcthat rotates counterclockwise at constant speed at an amusement park. At the location ssin yx3gc: 69ghown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuo: ;t*hefs-tq nusly moves in a circular path at constant speed in a counter- clockwisfq*h-tn s :;ete 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 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 path at coh;w,j0v 0bq9 6b2pfra; :vvyw o8pnltnstant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to poio yvj62wbl8rhf pb v;at:nv; q9,w0 0pnt 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 5 vuxyb2oat.(around the vertical circle shown. Which arrow best indicates the direction of the object’s instaut.v2ao5y(b x ntaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass cofu :f0g/qmg/ru;xvw9i( nw u 8nnected 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 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 st8xf0 ni/q vu:rwu/m(g9 ;ugfwring?

  15.23: A car moves with constant speed around a horseshoe-shapede gefwjfzboma,s2 f ( 64cd g;xd6(,9r path as shown with the arrows in the figure. Which on2 xfsdaj6(gz r (ew ;,b,gcf9e6mfdo4 e 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 pendulum 7 vg jguz9(xhq3lt4: lthat is relealg:q4 3u(9xjvg z htl7sed from the horizontal 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 from the center. *bmzuhb 4ltw(ak08lv /l+lo of a rough turntao+tbw8 0(vbllh* za/ l.4ukml ble 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 the object?

  07.19: What net force is necessary to k y)sg*z+lz9 cieep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal fr zl g)z+iy9cs*ictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on the w:9-2h/d2zxd 0 g r7ytzx vtg)p-x skwend ospgw7 yv zz w:g2t d0-rh/2x- tx9dkx)f an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal cird8:df oe o*m- g/+akhacular path of radius 0.8m with a constant kinetic edad m e+-*fk: ohg/a8onergy 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 attcm-yz5z3o 4z dached to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s.3- c4d5zzy zom 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 uniform circular motinfwo*oz j+-(z)g+z 7o gt 5cduon. Which of the following statements is NOT true? oo tojzd)gzf7z (5c*+-un+ wg

  00.19: An astronaut in an orbiting space craft attaches a mass m to a7 hixkm80 sl w.lr*ps5 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 s0xskl5 *prmwih8 7l. 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 Lfz 7y fw8,/upr to which it is attached makes a 90- degree angle with the vertical. The mass/,fzpf ur78 wy 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 bk c vka;xsa +ja/jo *r8-1 er+h2:ukyto the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of the c+k:xya hr +a8c2r ;-aujevj /b*kosk1 ar is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/1 sin j-vcmo 0s4cnd gq*m/86ks. 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 upwarcmdji6qv- sk*4cs8 ongmn1 0/ d force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical ci i63ptab*iy /vdyau90rcle at constant speed. The magn0pva9/yby6t i a3uid* itude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest from o9 k6i0qefyzyle; p8 sr 0a(.kthe 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 forcepa(s eoy 96zky; .e i0fqk8r0l 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 mas xg9pupr6 1n2zfx-gq3s is released from rer g32gxq1pzuf6-x n9pst and undergoes simple 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 applied to a rubber stoa6w/duv(qw m: pper 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 v, mqwu:d(va/ w6and the frequency f, of the stopper?

  05.28: A mass, M, is ah: ew0aa+af*b; 6wkwstd lp a-n(d+q6t rest on a frictionless 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 30 cm from equilibrium, what is the necessary force appliaw6+ew bsda q :ld-pawk; n*6(fth+ 0aed by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a cwcew*g,umi vqb,e zr3 l.n2,ag5dh2- onstant 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 lowest point of the c bhw*a-zri,wq,c3 ,. u2nve d2e g5gmlircle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal6mw6bep o,baw,3cx dj l *br.0 disk rotating at a constant rate about an axis perpendicular to th3r ojw0le. xm*6,dc6wba b ,pbe 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 moves about the oiwd+ -hk 0b rl9 n9.2xf6fgbtstring’s fixed end in a conical motion with a cki-.lr w0x9nfg ft+h9o2b6 b donstant 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 circular hme0)a/w:s5tx z/dcq motion as shown in the figure. The s5h xscmaqz: t0)//dewtring to which the mass is attached has a length 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 horizontal y/j gb*f4tkq6disk’s center. The disk starts ty4qf/bgkjt *6o 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 qqlg pjwi d5):0((iqt.0 kg is attached a distance R =1.75 m from the fixed5wqi0g:qipdt lq(j () 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, wiad3:ao4gv q i:vhm 4e:th initial speed 17.0 m/s. The object’s speed incr4 va3 gvmqeia h:4d:o:eases 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, st-dlr1xu+a (4ka *li )cfbcs +c4h+bod arting at the top, with initial speed 17.0 m/s. The object’s speed increc(s r cl++4h1i+xc fb)kuo -bdla4d* aases 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 o ct n67qk, bpdcidmbzp gc7j98 /)*/bkf 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 m/b 76,cd8kjdgi qtck9nb /p7m bpzc*)otion, 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.