95.02: An object shown in the accompanying figure moves in unia(n j0 (lo,;sy-m dj9j .gqrfgform circular motion. Which arrow best depicts the net force acting on the object at the qy((sogafm.d r9,ljj;0 -g njinstant shown?

  05.31: A child is belted int; ss7spvbv6 .go a Ferris Wheel seat that rotates counterclockwise at constant speed avsg 6.; svp7sbt 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 it :jzt1ldc,6u wa ;qe0t v.*drn 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. :twt1q ;ztr.d 0e d*l,a 6ucjv 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 h ew1t+ ):eig um51l0cxg-gvfat 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 the circle fr-chteguilw+5)ggmxf 1 ve1:0 om Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwisl*a )xue8eod32 spq7t/)t zvb .co/o ae with constant speed around the vertical circle shown. Which arrow 8qbz /3o eelpa2c. )uo/td)*sto7 avxbest indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass conne;zx2kbrht8y 0a ubd2/cted to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viek/h0ur xbzt;b8 yda22 wed 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 arouste6gf+;s/yvxj /ro 3nd 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 +jots6ersx;/f v3y/g the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an expc;qi6cd9lh -nsg 3h-veriment with a simple pendulum that is released from the horizontal c q3dh-l9v6- hcsi;gnposition 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 2.0g89pck0g s 6j*zzmj pcp/sa)3 m 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 object and turntable is 0.50, w apm3*09 jg 8czspj6z/k)scgphile 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 neces t7o89akq:fgzsary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontaf 89q7zkogat:l frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal uw h f;w *jkzik(f+xzt+zh 0l;i3dl;.acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a s tz0zi;+k *wh(fk.xdwj;uz3 l;ih l+fecond?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m ffcutot-; 50f ysg* 0owith a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass ytf*0gf o-us c 0otf5;as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in 2y y+h a fa-q0d73mzffkuo13n a horizontal circle at a constant speed of 6.0 m/s3h0 zauqm37f-+ yado1yfk 2fn. 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 acxxq6, p87x 2nr.gu tu rope, in a uniform circular motion. Whicxtgqp.nr x, 6uuc872 xh of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m tdj -ao*v7fq;yer u15 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 maintain uniform cirfqvty 1jura7eo* d;-5 cular motion would be

  07.22: A mass m is pulled outward until the syq gvm)y90 mz+tring 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 stri9 0mz+q ygyv)mng when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly ter- y1q1-m vza(y7sxv ihrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of t a(q1m yzsixh1- vy7-vhe car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a concfk npkem,55 ;cy n*t0stant 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 ex0,5 p nkk*cm;cfey5nterted by the road on the car?

  97.13: A small sphere is moving in a verti o kp13f59 (pxmxim,o,h wpaa0cal circle at constant speed. The magnitude of the net force on the p, h(1xwkmi,pa9mf 3o5 o0paxsphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest 6lg cxoqlo 6 ;4rrg ii5zd3+k(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 thox(l z 64ioq;g+5rik3g lcrd6e 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 fi3rli,-m f:g,gl(n aa orms 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),-g amaif(r,3lginl, : 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 0g 4 cfa3x ,td/whyk0:fip7pz a rubber stopper 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, and thekc f4papx wd0yz,7f3tg 0hi /: frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to zr4/ f5;rfh fh3 z61rtbyf 4rh 6f4hfsan ideal horizontal spring th5 h 36rf4z/f4zhb 1f ;srtyrh6r hfff4at 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 applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constankwbaj45uyl1gg(zm8 xo. k. z8t 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 ugl a k41w8zg5om(y zj8.bkx. point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a xc hc7g 4,ha: 0m enm6d(ha/1r uks;bohorizontal disk rotating at a constant rate abou7anm1csk 0/e;hharu4 dxo(b: m gc h,6t an axis perpendicular to the 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 i8( .dbqp,kckks connected to 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. The string has a.qdb8 ckk,(kp 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 motion as shown in the figurpjn :pk:. mm,(dtge x9e. The string to which the mass is attached has a length of L = 3.00 mpt m9:jkde( : p.g,mxn 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 p+, b dhxac84tsuo/f 030.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular acco/ 0d +t,ux 48sfahcbpeleration 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 m a fx 07xxq3b;r 7:om4z7xtdlpass M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure3 fx zpdx7rb7o4la:q7;tx 0mx . 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 ata2gpnsp -): 4ra bs:fq the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through pfrs )b2ap-ngsq:a 4: 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, with initial speed hps 1 :-b/h yrqqonyp;ri4..x 17.0 m/s. The object’s speed increases unifo xh; p1-:/s.oby hrpynq4qi r.rmly 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 ki m)/f mo6aj;rg block rests at the bottom 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 place in the bucket. When the bucket is/ m jim)ar6;of 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.