95.02: An object shown in the accompanying figure moves in ci dq8ezva/7a5zd gpc0itb i+-96d-muniform circular motion. Which arrow best depicts the net force acting on the object at the instant shown? 6d9vdd8tc z i07bq--ip +e5mgaca z/i

  05.31: A child is belted into a Ferris Wheelq8)asrx ;d)xdi 1 dn 0agy7t+o seat that rotates counterclockwise at constant speed at an amusement park. At the locad dag0irx7nyxstq od)a ;) 8+1tion shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at co.hxm;pskvsi z fm d,/ b/(cjj,)p-1a)gs irt6nstant speed in a coujszm),i.i,adgm s;/sppj - c(vb kxt)6f1rh /nter- 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 circuh sw9qy3g;-+y0mh whhlar 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 thwh 09w-yq3;h+syhmg he 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 circledug .m3v).n u vo muq/wcd24m5 shown. Whi.4mgcv5.nd ) mvuo2 q3udwmu/ch arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connectm 12-ia41)sfwuu racoed to the end of a string counterclockwise in a hwus1i4oacumaf1-2r) orizontal 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 string?

  15.23: A car moves with constant speed around a horseshoe+ an(g id: hj :i,ynwie w3;fw3asea/y tz*2-c-shaped path as shown with -ny, a sgd iiaynw +h/we3zf:3:i; *je(2twcathe arrows in the figure. Which one 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 simph-f ld /5kv+dcu+8jnwle pendulum that is released from the horizontal position at u8hw/+lnc+dk5 j- vfdrest. 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.qoonzm ;7+ kt6 o v;olmbs.w,.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 objes ozm . o; v+tbk;7n6ooqlmw.,ct 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 /5 bax vry,+qn1o ozq6is necessary to keep a 1. 0 kg puck moving in a circle of yv /q x1oz5bq +ao6r,nradius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal i. v hrirrpc68kd 9 4zj1k4t1hacceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a 9hit1p 4rv18zjih r6r ck.d4ksecond?

  09.24: A point mass moves along a horizontal circular path of radius 0. u w9tvkp*a0m 5/jre+fqp a3t3fy(6 yw8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it fr ep*930y (f6q a t5p 3t+avmjww/ykumoves?

  96.24: A 2.0-kg ball isfe dz6p(zp5,szaz21f-gzf 7 p attached to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See 5pfz,1sd7e fpg z-( zfpz26zafigure 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 circuleq s+ i7;,g8ygkah dk2ar motion. Which of the follo8+g hkk7yaq2ig,s; e dwing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m t:x3qotgj6j.* ;sgqwa o 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 maintain uniform circular motion wo s.qw :*x ga6;jtgqj3ould be

  07.22: A mass m is pulled outward until the str:c kbuutm 96u4ing 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:u4m6bu k9c ut the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the ri fjaqk69l u i,:g2wb0wght. Assume the 9 w: iabju,lf60qw2gkcar 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 feel weightless:

  17.10: A 2000 kg car moves over a hill az+6j-f ya-hrd,;:tjcgb xn/ mt a constant 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 in6/ trfy -z hjj:;nc,g -badx+m 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 constant speed. Thog)eq6 c /t6ike magni /t koc)egqi66tude of the net force on the sphere

  11.47: A simple pendulum of length Lhr*oi j4fhn, 7ofk q+*oasa point mass M released 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 ma4ki*o,h+f rjfn 7 qo*ognitude 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 stringtefey 3/4.q1 8 2ecwuxh,px tds:w/c l forms a simple 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 pdft/ e et.u x xch2/4l8cq:p1,eysww3oint?

  04.41: A centripetal force of 5.0 newtons 0dp k5f.kaj, ebn1 uj r8gf6ov5m+ ya+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, ap8+ gndf +5fovmy jur aekbj01. ,k56what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is 80em nq,hez5u at 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 connecehzuem5 ,80qn ted 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 afez e :sq-(2jy 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 lowest poz2js eq-fe( y:int of the circle?

  14.23:Two small identical coins (* ihr thvhh-v6./+xvflabeled 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 dish .fvx+v6*h ihrt h/-vtance 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 mo* gn u6yccru9 d0-ncq7x56hi bves about the string’s fixed end inrcx6h5d9ui gu0n qc76cb-yn* 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 circular motionwckk5xav3.(*bb2n v e as shown in the figure. The string to which t 2n cwav.kbk*ev(b3x5he 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 z h xf/,prrp,5rest 30.0 cm from a horizontal disk’s center. pfrz x5/p ,h,rThe disk starts 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,zwr8 p84/)zp rcwkvy M = 2.0 kg is attached a distance R =1.75 m from the 8,rwpz 4/8zr) pkycvw fixed 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, with initial speqv*j6) b sp2en(pjwci)ptv ( +ed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclp)ji(vjc qp6b*+w t)psn2v (eockwise 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 i3n*b5zur:y /jxs0 qg top, with initial speed 17.0 jz*rbn/5u0gy s :qx3 im/s. The object’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 time for this motion?

  17.38: A small 2.0 kg block restsde , y:qpno9(k ;tk j7t+bab,a at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reachbk 7 onjtq,k9:+a ,bydt;(e apes 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.