95.02: An object shown in the accompanpe3)vt qqe/t 9ying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant shown qeptvt9e) 3q/?

  05.31: A child is beltiw3puu b:+)bqt6azmf-,w s*fv 3rc0 qr 5nq -eed into a Ferris Wheel seat that rotates counterclockwise at constant speed at an ,w5ub+qrbtu np 3qmcefr*3s )a0q6i :w--fzv 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 a circular path at constant speed in atpf.(g2-y v oy counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point(y -ypf2.ogvt 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 path at constae)1jlw4c;9uur je t o4nt 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 haelt49)1j euo c;uwj4 rlf-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 t 9300 xeqz)njgp4d 1qpohf 6slhe vertical circle shown. Which arrow best indicates the direction ofjqs g6 lhf0dz31o)x0pp4nq e9 the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connectedgt z9yt+ igc g,5-h68svxfvn 8 to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from c9x-+5f tvgy s886gtzihn,v g 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 pa86/lko,jce c3f et (ggth as shown with the arrows in the figure. Which one of the following ckejg3l/ctoc, 6g8f( e hoices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experuv 7a(rt/kwy5iment with a simple pendulum that is released from the horizontal poktvua7( /w 5yrsition 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 kj dt1;ye06)-dezd(uk u) kk iw+pwf -cg) point-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 object and tiw+ ek(e-tpk wyu6f-0)d)dj ; 1kzu dcurntable 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 a circlih(u.bavsm5 .shx,z8 e of radius 0.5 m on a horizontal frictio z(8smi.hu ,.v5hbxs anless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) onl6fit.tsb z-z8 .fe ;r the end of an 80-cmzlt t8f-6bf.i ;sr. ez string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal cn0w-e4yzc 6cfxg9 k3f ircular path of radius 0.8m with a constank9 46 ycefgn3wcxz-f0t kinetic energy of 128J. What is the magnitude of 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 horiza5y c9crrdpm u2j6:tzd)s g6( ontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revoy6u(5 a:g mjr dpdzts)2c6c9 rlution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform cir ismu(m v4 r:cg6hp4 h3tr;q3dcular motion. Which of the followinmh 6 3vhir;mp4sct(g qu: r3d4g statements is NOT true?

  00.19: An astronaut in an orbit4 kfppk83,h,:xxim e .z6:j hpd ol da)m.*areing space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of the circle ipd *h)a,l k r4..edm,ppz3xf8m o h6ie:a:xkjs 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 until the string oa8 *x2x hdzym,:.t qfjf length L to which it is attached makes a 90- degree angle with the vertical. The mass is released from rej: y hzxat.,mq *x8fd2st and swings through a circular arc. What is the tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is travpwwtdez 56(ftp,+t2qzvh9, xeling on a road in hilly terrain, see figure to the right. Assu(hw9+v6 tt,zp5xte2dq fw ,pzme the car 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 at a constant speed of 12(r3mk tudynb hbk457wi)8ig qvft6 48.0 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 by4d4g(5 rk w3 67ifmnbkv8)hbiqytt8u the road on the car?

  97.13: A small sphere is moving in a vertical cqqnr umwq75)afs81 oa :hwe:4ircle at constant speed. The magnitudeah8) :4sfo1aq5qr mew wu7: qn of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M rele otiua.5+gli2*gc0cbnry+ j0ased 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 blia.5c20yn cgi *+utjr 0go+ 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 at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a sd zn/(yt aj vxyxqd965on,y4gmw3 8h1 imple 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 t/t395vjxy dqm8 ,yz n6odhwynax4 1 (ghe mass (F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is app. z1+d5tx aytplied to a rubber stopper moving at a constan5ty. + zxd1tpat speed in a horizontal circle. 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 restpzrf1xp(ujhv0 7og6) 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 cm from equilibrium, what is the necessary force applied by the person to hold the m)0z1jrvpghfpo6 (u 7 xass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 3.24 m/s in a )t0b28vc7p2y lbs yxmvertically-oriented circle of radius 0.75 m. Whatx2l82ym7b b0vcty ps) is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identiibnf4b 6yjmx5j(1k ,hcal coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about jkxhjm 6,bi(54 yf1bnan 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 is connected to the end d,m n:x/m q+xl59j ezcof 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 length eq, :zxmnj+/mc x9 5ldof 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 unifo 8:d6w0u jfalzo*ib m u 5e5iub5d-hk+rm circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of -d*uo8daf5 wh+i5bubu 0i je:5kz l6m $θ=50^{\circ}$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 wd5hh*.1+d8/iu nwbuoq bj; q0o3ve ufrom a horizontal disk’s center. Tewbd*wh5q+in3 vu8ou.d/qb1 ;j o0hu he 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 objectdddpz8lz,lt4 4 9eds. with mass M = 2.0 kg is attached 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 constant8espdzt.dl4ldd, 49 z 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 speeda j5z1m:2q lqc 17.0 m/s. The object’s speed increases uniformly uzlq:m1 jqa25cntil 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 7mo/d nwspj3 /initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclop //onw jmd3s7ckwise 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 bottom of a bucket. Th tn/biz9(bbkw z.e1b4e 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 bub9bzt 4ki(z wbe.b/ n1cket. 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.