95.02: An object shown in the accompanying fi)k tcey ms.8f(qx198v ze2 r6gx 7pirqgure moves in uniform circular motion. Which avr q6(xrecziy8m tkqg) e1f x.27sp89rrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris ;*uj2wz o.maiclb 5*jWheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction beswj 2ji .lm;z a*o*u5cbt represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuouslc ;ai8jrk0bj5y moves in a 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-w50;jk cr ja8biay 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 constan*g,o b;0e- htp;mxnk rt speed in a counter- clockwise direction. Consider a time inter;-repxbnhk, m0 g*ot;val 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 wie6 om/p*oeb81no sfn)7s vwx )th constant speed around the vertical circle shown. Which arrow best indicates the direction of the objectfpb6)s xnem so oe71v)8o*/nw’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string counter1; kcdlynhp+d3(o 3ke clockwise 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 t+ pko1d( khcd; 33lneyhe path should she let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped path as 6;q;opbr b 9avy5 job:mnd04bshown with the arrows in the figure. Which on;mrbn4v 0 ya96jo5qodbbbp; : 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 angs3 c219y h6z)xvhhh )so py6p experiment with a simple pendulum that is released from the horizontal po h61 6yxhgcho2 pvp))sy39zh ssition 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) poinkgj5z,w-m6dq itty8 ka( -7;pe;su2k rrmby0t-like object rests 2.0m from 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 ob y;mkqg0ysttrm; kzkrb wpa-8 ud(26,e7 -5jiject 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 k.p6tl kh-y*zlq:v(wt slr /,in a circle of radius 0.5 m on a horizontal frkw-/ky 6 :zlt.(rhtp,sv l*q lictionless surface with a speed of 2.0 m/s?

  05.03: What is the cpyo1xt p1dl li2c5z ycl757:r.m2goqentripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant zll7pyg2cc: 5r liq1x57mo .opyt d21 rate of 4 times a second?

  09.24: A point mass moves along a horizontal circuli6s*v(b bt:k rar path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass 6isb:(v tr*kb as it moves?

  96.24: A 2.0-kg ball is r5 /(pzuz no4n;tq,wfattached to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done ofz nwzqn5/ u (;opt4r,n the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform c:1 qmufpm -ow79rko s7ircular motion. Which1q:7p -o7 srkfo9 mmuw of the following statements is NOT true?

  00.19: An astronaut in an orbiting spaco 1rw8 (ubxs1fzq (lu-e craft attaches 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 double the tension required to m1 lbx1 f8squ(oz(wu- raintain uniform circular motion would be

  07.22: A mass m is pulled outward until the string ookl, y8x4dka) f 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 the bottom ofthe,lkxyoa)k 8d4 arc?

  94.15: A car is traveling on a road in hilly terrain, see fieu 62x 6v+-d*rrow mukgure to the right. Assume the car has speed v and the tops and bot u*xkr dmu-e+6w62 rovtoms 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 hill at a constant kkwfeqr dju4 idha;xnu :5(eaj(31 8,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 the road on the ca f,unq:(r xewjdi4h;jku a1d5k 3e(a8r?

  97.13: A small sphere is moving in a vertical circle at constant speed. Ty1h49nya 94egd:(s x lxj sv8mhe magnitudy 8l9g:4y1eassm h(n9xd4xvje of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released iwp/-ot,-cs:jha0gmr b d/r1from 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 for1am w -r,sob0/g-td / :ipcjhrces when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simple pendui2,ivf4 z atxlo :/a8jlum. 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 th,ix /84tz a:ija lvo2fe net force acting on the mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force o : s ;yney75jjvq5ovw9f 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If thy5ns97yjw ;v5v jqe:oe 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 friv+q eg7n4 bnu7+ k6jpnctionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium anp 6j en7bngk7v+n+ q4ud 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 of 3.24 m/s i-ov1q *rk (xe;:in mszn 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 thrnkmo 1:*;-v izxq(ese circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horx96latc+ y.cwizontal 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 l+yt.xc69a wcdisk 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 stria+ n2k79 v6h,q uzxwig-v/osmng and moves about the string’s fixed end in a conical motion with a constant h mai+o2v9-s 76zq k,w/x nvugspeed 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 uw6a70 szw j/ kgpq*:gligd74pniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and fa67p47sg/0 gqjzk lw dgp w:i*orms 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 horizontalqj,c5hzvzc4) ux*v-ji t0u5k disk’s center. The disk starts to rotate fzz0cux-cqj4vj kv5 uth5 ) i,*rom 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 objectp7tug8y ih0rwq96rp/o 5imq , with mass M = 2.0 kg is attached a distance R =1.75 m from the fixed centmpw 0prog7rt h/5 q,iqyi68u9er 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 r(noj n/0- (k-umeewkne76zl circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has mu -0n /k(rj6zmnekw-l 7neo( eoved 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, o -kne y1k 73q;qapzd+/ ,lajlr 2abf,starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countercl/q2 lr7on,q1zb; f-aykale3,ad+jk p 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 restsj(z1 qdl(b1 tb8 b8x2il gq2sw at the bottom of a bucket. The bucket is spun in a verticali(8 1jql d 22t8bx(w1zglbbqs 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 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.