95.02: An object shown in the ack-f,hzc 1 yo)kub9f:e companying figure moves in uniform circular motion. Which arrow best depi)9f:k bh1,fok-ecuy zcts the net force acting on the object at the instant shown?

  05.31: A child is belted iau)yr1 q 5z9oknto a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat o zry 15uqak9)and belt?

  08.14: A particle continuously movt*(c (vmw;rtc 6 a rvk.v*g9aoes in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moa( ;kv r vtm(ctw*oa.9rv*c g6ves 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 continuousx5yzd y8:oo y6ly moves in a circular path at constant speed in a countero y:z6 o8x5ydy- 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 acceleration during this time interval?

  15.07: An object moves clockwise jc41l 4xd4s yrwith constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’s instantaneoydj1c4 lr4s4xus
acceleration at the point labeled X?

  12.11: A girl twirls a small mass conn6zlvglkc, :mx t-ln,j v;s8. aected 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 above the twirling mass. If the girl needs the mass to pass through the point labeled P in the figure, at which lettered poin;t,s8vll ,xmlg:6v z n-kac.jt on the path should she let go of the string?

  15.23: A car moves wi:ljd*g9*j +0tjt0w 6dzfpt mtth constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choicf+ mpw0t0j *jt:tjdd6z l g*9tes best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perf/ ak5sl 0vxd,torm an experiment with a simple pendulum that is released from the horizontal position at rest. At t v 5dxasl/0t,khe 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 thjcdo-1ldccsx 7 +g-x2p6erm4 e center of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 seconds. The coefficient of ki1l6cd+d com-x 247p cjsxrg e-netic 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 1. 0 kg puck moving in a circle op) c ya)5f)w5)sn3,iprj pe.kvg s 6rgf radius 0.5 m on a horizontal frictionless surface wit5 gyessp v5)gj)p)3 icfk,pr) r6a. nwh a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on th qzblx2jt 35g;e end of an 80-cm string rotating aj;t5l2zxb q 3gt a constant rate of 4 times a second?

  09.24: A point mass moves alon:biipj+m79z gce sz. 7g a horizontal circular path of radius 0.8m with ab7c7g9si+.e: mz zjip constant 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 / ac ogv,7-jd py,mw5tstring and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done /g7-t op , cmj5vadw,yon the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a unifor7ax: 6t8oi meeooun;,s2 dtblm 1( ;ahm circular motion. Which of the following82e;( a hl;6tox i no:7s1bmtd o,uaem statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a string a)k,vm) u ad3vand whirls it around in uniform circular motion. The radim3k),av ) advuus 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 would be

  07.22: A mass m is pulled outward until the string of length L to which it i d f8z,4:wz2odpd s8sc(.yroybl;4 qys 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 th zr2dzscq4o:ydy;s(848opl. bfw,dye mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see g ( kzrk;;3 cl cjvia-m5v,ce+ +:mmbbfigure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius ofzm5jm;-c+e3b(+; ir ,vc:bkacmkgv l 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 constasl7+d xlf9/l1 qi (rgxnt 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 2 l1 x+i7/ lfgqlx(drs95 m, as indicated in 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 gk h gzu69dwcs28cljk4w kh 340f.w/s constant speed. The magnitw k l ud h 6gz/kk2s3csc.4fhg9w0wj48ude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from resz3vs h u jj5)/y:,6hliyf4 dslt 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:f zjuld 3js45vl6yi hys ,/)h 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. T7/ pz r,mnzt+xhe mass is released from rest and undergoes simple harmonic motion. Which one of the fo +7/ztr, pzmnxllowing 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 point?

  04.41: A centripetal force of 5.0 newtons is ap2h(j*) wyjsytt xxx*0z,q1fpplied 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, what happens to the speed v, and the frequency f, of the stt*xqfj x x*0,p()12wyj hsytz opper?

  05.28: A mass, M, is at rest on a frictio-: a nny6rtor3(46fvhag vt2lnless 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, r( -vy ahal tgt :62ofn3v4n6rwhat 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 coy) ly hftaf)6t(hkqatc /fva-)0 1l)jnstant speed of 3.24 m/s in a vertically-oriented circle of radius 0.( hla ta0jt ff)-)1la)tqy cyfkv)6/ h75 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 yd,exlmr 7 h/+t +qa-tX andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to themt+ ey,7/ -athr +ldxq 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 of string and moves aboun: *w 0t;gwslkt the string’s fixed end in a conical motion with a constantw*tnw l:0k;gs 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 motion as shown in the fv16w3)2tcrgctfprlquj dph :8 + dk64igure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of d vdt )+gcu36 hw26p:rpt f4cl8qr1jk $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g is atg8xs-c600qoty1fx dw rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its c- t0xwf 81oy cs0xgdq6enter 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 wi8/ zp f.q;lfjjargkql, c3- 9sth 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 constantj l;, 83jp-.fg/ azqks rl9cfq 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, n1xe9.buj ja2 with initial speed 17.0 m/s. The object’s speed increax .e91njj2u bases 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 final speed of the object?

  16.40: An object moves in a circle, starting at the top, with in9p(fx/4erfktc na 73vk7ksj6itial speed 17.0 m/s. The object’s speed increases uniformly6kacktk prfs473n7evjx /9f ( 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 rest-* sc :nlwbmkw+ppx 7(s 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 bucx pcbwlw:m kp7ns (+*-ket 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.