95.02: An object shown in the accompa)odp16xuuzt* nying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant shownx6* do1tz p)uu?

  05.31: A child is belted into a Ferris Wheel seat that rotates counte b01tsa7h ,yabh)d;zc c+ti8 -y)fyg frclockwise at sc-,ai g+7cb8aytb1 hh fdyf)z);0tyconstant speed 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 a9zokf(9sb86 klvssk6 mns-a; circular path at constant speed in a counms9k6nklfs6-a vs z k;sb(8o9 ter- 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 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 paest/5:y( s jhzzv tmj7(-vtq(th at constant speed in a counter- clockwise direction. Consider a time inq5(yzjm v/vt(e tsj7zt -:(h sterval 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed around the ver i-ea8; k6oy pe/w*vut:/nwfp l(as6p tical circle sh:ew*s/p ;-(va66o ple/8na utk ypwifown. Which arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the eln (n 3io74gj:s*gvftnd of a string counterclockwise in a horizontal circle above her head. The fiv gns4g (ij3 ntf7lo*:gure 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 ch nb::ny 27t xpm)(6l,qbe3, cdtbdohonstant 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 the average acceleration of the car in tecdo3 lp6,h d) q(2t,bmbyn:nt hbx:7raveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple penx2g t3bs 91bsp3ue(kcdulum that is released from the horizontal position at rest. At th k tg 39c(xe1spb2ubs3e 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 ro 7h6j7ik g 4:s9vvgg3)j2. g p1egzltqavk:ucugh turntable as the turntable rotates. The period of the turntaggv6e4g jk):pa7 j qh 1.:uvv3c2tg7i9gksz lble'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 keep a 1. 0 kg puck moving in zz ydqcuadc 1z *, *rv;(tc75va circle of radius 0.5 m on a horizontal frictionless surfacea,tcvdcz qd1 zr; (uz 5*vcy7* with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleratio5g+, ccv2nbn nn of an object (mass = 50 g) on the end of an 80-cm stringc,n b+vg2ncn5 rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circulard2cbn7(jnd;d3) fr av path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as itfd7a)cr(nvd3d;jn b2 moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled l9kfip jl4.9vi ud:e2in a horizontal circle at a constant speed of 6.p k29u:vf.l9idle 4ji0 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 o (+sicb y6qaywa 1l(,rope, in a uniform circular motion. Which of the foll (c6wsl ob,i1a yy(qa+owing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches n,w6 h o(ct).vidgt2mh8 rt6pa 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 masg6w,vtc6 t.i 2hrt()h do8mpns, 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 -c0-g5zv xe(wqhkw 43xti yz: until the string 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 through thvhi:0zqex- w gcw3(x4 5-yk zte bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see fml5k va :/,3b qduizq)igure to the right. Assume the car has s)3lz iba mqdvq5: /u,kpeed 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 car mo/1 w*pcj2otow ves over a hill at a constant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be approximawjow1* tp2oc/ ted 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 moving in a vertical circle at constant1w nrn.7kyc3gtc s:ma-2et7oo;ru e 6 speed. The magniton a2gw ;. n6ekysr-7tructo 7: mc31eude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M rel2xxx;- 4c ado:n;klurk 0ti(leased 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 tx4:0 ndk( x2l -axr;;ilkcu oat the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a s02s0g 7q*m rrmy,oa qmimple pendulum. The 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 gravitational force on the mass (W), and the net force acting on the mass (F) when the mass swings through its lowest mrr,0 a*7om sym2qq g0point?

  04.41: A centripetal force of 5.0 ne, e daox90g.yc,q3)ujuiaj 1l(gii 7q qj,3e gwtons is applied to a rubber stopper moving at a constant speed in a horizontal circ,3cj 9dg ojiq3aaqg i)7 ug0lqe( 1xiye,u j,.le. 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, connected to an ideal hzs l44 k, ks:r7rsg.irorizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium k r:ks47r,4g s. szilrand 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 kg mass with a constant speed ofzsd px(jnx,:7 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 low(x z:pn,s 7dxjest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizf4m 5x(f7- xhbxqv r9qontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the coins from the center of f4 7rqq- xvm(xhbxf9 5disk 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 ismo)+ elct,c:a connected to the end of string and moves about the string’s fixed cm, tce:a)ol +end in a conical motion 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 in uniform circularl mjxev/1y0s6 motion as shown in the figure. The se16vlxm0/yj string 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 dxj .-frmzq16 pisk’s center. The disk starts to rotate from rest about its center w1.fzm-6pj q xrith 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 att8nsk 4)p0 cmi2hfx1ucached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constant angular acc8u0c 1phi 2c4) kxsfnmeleration $α =5.00 rad/s^{2}$ 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 spee jltj+ir qkdg:di.:mvr0(l,,d 17.0 m/s. The objectt+dm:0:iidk r llv (g ,j,jq.r’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 final speed of the object?

  16.40: An object moves in a circle, starting at the top, wmf08tbfjs1 /-xvj,it ith initial speed 17.0 m/s. The object’s speed increases uniformly unti0xt1/f8 , v tj-smjbfil 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 b0fop1 0fmq-ge ottom of 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 in eqgo10m0-p ffplace 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.