95.02: An object shown in the accompany+k*m3 spft* qsing figure moves in uniform circular motion. Which arrow b 3fptqs+ *sk*mest depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris W(0 6oe+ erdxi oily;er rq w.(q7b:q*aheel seat that rotates counterclockwise at constant speed at an amusement park. At qi6o b ieer; q0ard+w l.qex7o*( :y(r the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuouslyo utorxbt5axdzf8k1/+r 8p -( 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.x1ufrr-5k oxa8tb 8op+z (/dt 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 movsp4kf5 9o o(em h2z9byes in a circular path at constant speed in a counter- clock boh5spmk ze9(29f 4yowise 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed around the vertical circlc1za)kuy (l f)e shown. Which arrow best in)afcu k1( yzl)dicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass coqp( cj9xh1/j .y+ygj )qt1gognnected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline /)jg+1.19 ytqc(hj qjxp gyo g 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 cons+1my6ostus3a c4c rcy1 tu8b2tant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices bes13486coct1c mbastsury2 + u yt 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 simple pk9 :gx9o:y+a7 9;mmu w obrw1lzgd2rxendulum that :gmzw amk x9 9: 2g9r+xbou ld;woyr71is released from the horizontal position 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 2.0m from the uk-2x-49 hog9bsxv pdcenter 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, while the coefficient of static fgp-2 4v9s-d o9xkxhu briction is 0.80. What is the magnitude of the force of friction acting on the object?

  07.19: What net force is necessary*y01lv7r.fw.cx 3 c vnodkke+ to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0fwdkrevx +kc3n 0c 1o7*yv.l. m/s?

  05.03: What is the centripetal acceleration of an object (mass = 5m 91-288 pa ko9ymelau:laa gn0 g) on the end of an 80-cm string rotating at a constant rate of 4 times o:8 a me2aglmuaa-n9pyk19l 8a second?

  09.24: A point mass m pp0xk ys;:y+z,u /etz3kvgs2 oves along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of ,s3ktu:zv;gppe/+yzk2x y s0the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m stre9aqpy4b vu3 7bupi,2)lfsmp 63 5oc qing and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolu yf eap,p3 c54vq3)mqs2lu 69biupb7otion is:

  99.22: A child whirls a ball at the end of a rope, in a 1f1*sxsj k6y pe:jdyy8.x,gpg. ny9a uniform circular motion. Which of the followisgne, ypyx9jd:1 x y6g 18f.ykjsap *.ng statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a string ye382tbswconz+z5 *u7 h 8jdf 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 thz nj8*7+be h8y dzo2sc 53wtufe 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 of length L kom eiq y) onpe,jk ,5/aorvgh)2x2+5to which it is attached makes a 90- degree angle with the vertical. The mass is released from rest and swings through a circun,k2xo,+ 5gia)pm q 5oheky )oe2r/jvlar arc. What is the tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terra i22cosijn04)z u2i gr,7. wmv5h yytlin, see figure to the right. A7i.ihmyl02 ,4)jz2 nut 2orig5 vwcysssume 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 12.0 m/s. At th-jd g90 zma h6jeonas7i;q h6pnv 2/5ie 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 follow50ihp/;7hia-6 m vnj6a2 9qog djzsen ing 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 icpy1 vqfh1p ;kqb56b ,0cn4k/p k 6cfconstant speed. The magnitude of the net fo yc16c0qhpib c, f4 bk51pq6/;fkvn kprce on the sphere

  11.47: A simple pendulum ohg ehc9 -g0w831 mestqf length Lhasa point mass M released from rest from the horizontal position shown. Inghe8q 1 ge9thc3sm-w 0 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 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.,9vorkzl nn9:r)lc ;z3ps+ ue 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 for)v9l+rz nc;o:9 nlre3skp,z u ce 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 rubber sto pv )yla+7zu2opper moving at a constant speed in a ho2 vua+) lyzo7prizontal 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 re4: ugo;(sqwzh dih2s: st 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 t4 ;qo:w2zu ssg(d:hhi he 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 66 q/p8qpy jsn3.24 m/s in a vertically-oriented circle of 8jpsn6 y/q q6pradius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X a xz.0/scq6msc ndY) are at reston a horizontal disk rotating at a constant rate about an z cc xss/6q0m.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 c,3;mmjv/on9wyf ss+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 length of 2.50 m any,9cmov+/fw 3m;n sjs d 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 circula,qk 3vwqa *x6kr motion as shown in the figure. The string to which the mass is attached has a length*xqk wv,6ak3 q 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 rest j) 0 awdnc:y79ibyr)p30.0 cm from a horizontal disk’s center.9 c 0raw yn))d:jpiy7b The 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 s3ql wwq1 k.)vwith mass M = 2.0 kg is attached a distance R =1.75 m from the fixed center.q w3w lq)v1ks 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 in 7u/o, bink:yur;t4 vmitial speed 17.0 m/s. The object’s speed increases uniformly until it has moved count/7 y4:u,i kvb;n outrmerclockwise 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 initial spee;nj 9gm*yz9 3(twu utnd 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise thrugj mu( wtnn93t*9y;zough 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 buckegdd((6ao5lmp/ gjb h1t. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, ldg5/mj ho(pda1( gb6it 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.