95.02: An object shown in the accompanyin8y np :5 c.7b)bejmr.vegr*ngg figure moves in uniform circular motion.mnjgc. n7 gy. *bere:)p5vbr8 Which arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel s1ub( 8aubb e u (.h-hy;sd 4lrg6w:qbmeat that rotates counterclockwise at constant speed at an amusement park. At rhlaebgu1 .usbu((my4;8b: db h-q6w 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 a circular2+l;, (rah h*fz1nrhryyo /ya path at constant speed in a countrz y h*1r+/h yar(nh y,;of2laer- 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 qghf/dztz;:.g9(nq foqq i.+ path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves alh:fog q ;9. zzni+qtqfd/(g.qong 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+p;.pxs 9 oeodtical circle shp+ o 9x.p;deosown. 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 k :x:jpa11 wwxthe end of a string counterclockwise in a horizontal circle :j 1xp:wk1wxa 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-shaped pa*c 8gn5o2 1v7ranswfs th as shown with the arrows in the figure. Which one of the following ch*s f1n noarvw7s5c2 8goices 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 sily:(o+d ee. bvvin)baj+) kg5 mple pendulum that is released from the horizontal position at rest. At the moment shown in the d i v5v bj:d +)nlogyekbe+(.)aiagram 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 u)b/m, yell,iei uj ttjy(4q5(j/s0z rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotationy jy( liizetu4tj5 ,u m0,)s (jqbl/e/ 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 1d901ijmkmt +z . 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed +ik0mdz1 jt m9of 2.0 m/s?

  05.03: What is the ceb)ys0yvbe l 3 .kgw*g,ntripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rot 0wlyyb3g.bv k,egs* )ating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular 1pi;7 cg6u f n*qar7itpath of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude ofif ;rcq761 7iugatpn * the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horizontap)em zi8n3ad 1l circle at a constant speed ofmi31edpaz 8n ) 6.0 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 thesjfrq)l 1 9w6g end of a rope, in a uniform circular motion. Which of the fofjsr)1 9lqg 6wllowing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to hyp7/b7dip1o kh +g7fjk3xeu 8h7b i; a string and whirls it around in uniform circular motion. The radius of the circle ho7dix p7;7/1 i ue783hyb+ bfkkgpjh 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 would be

  07.22: A mass m is pulled outward un:mvlnvn/n / rz6j 6z-jtil 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 th-6r6 n/vlj/n:zjvnm ze 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 to the right.6psno wj -do55yb8i rr )5nko. Assume the car has sp5p8djwo5iynork5rs6ob ). - n eed 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 at a constant spt w,t o0s;y+13dogwu - ;wkhg8l, epmueed 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 upwar t0gw-w ;m,twkup e38,gh1 d;yo sl+uod force exerted by the road on the car?

  97.13: A small sphere is movint4juz8oyd s f 7s*.,ufg in a vertical circle at constant speed. The magnitude of the net force on fsu ftj d7 *o,8.zy4suthe sphere

  11.47: A simple pendulum of length Lhv ggmyx3) fboin6q73 au;3is1asa 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 gx) 637;o s3 iiaym1nv 3uqgbfrepresent 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 at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simple pendulum. The mass is recyd) 55 ljgz*)y0ddd nleased 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 5d g)ncl05dyydjd z*)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 r6j8 msxe2n: 7uwf;,ib mj( rlzubber stopper moving at a constant speed in a horizontal circle. If the same force is applixm8726 :wb i;l zjrm,fusje(ned, but the radius is made smaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is8tdfk/tt2+g+)g ruut 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 connected to it is now doubled to 2M. If the spring is extended back 30 cu tg2rtk f+8+gt/ud)tm 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 ofrry7gz u7e2iep9r3r2c: g :xi 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 g gze9r2:r:iy i r xu7pe37cr2lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at restv,v l/*d8c(i xmzg(u:np qws7on a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the /zvq:n*( pm7,ugcw8xi l sv(d 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 tjn+m ejuw u6p2e52fk ;suyu/;he end of string and moves about the string’s fixed end in a conical motionf pj;u+k25us je;w2muue n 6y/ 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 i1i 78fqahpvv0wx5r0gt3xj l; s in uniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.05wq0l jvfgp h3x1v 0r; a8i7tx0 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 )**.eaaan 1y0knqbszma .vm1is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center)mas0*anaa z1*1v k nymeb..q 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 masa,woq v3xn8qj; 0eva52p f; mq:ujfp+s M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the 03pj,apj qvq qafe 5u8m: ;x;vo 2n+fwfigure. 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 movblu60j4; 8fa su0ozrj;gp*(rxkidi0l nnp+ 4es in a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases u +jd 0;;l8o lb00k urgn4s4zp6ar*ji xp n(ufiniformly 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, with iniw5 2:-3j, ljkd w 8y;y-m*odgfgolidytial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwi -gl , w*ydd-wjo8 di5gj:l2ymo3ky;fse 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 kk;1w 1cog2z17 tmjd yng 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 fay1n2od7t 1jwmg;kz c1st 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.