95.02: An object shown in the accompanying figure movesp 5 u6tb+j7x,3 nysqkp in uniform circular motion. Which arrow ,p+u bs 76qtp3k nx5yjbest depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotatyzuh4u j3i*0 ll7u9lges counterclockwise at constant speed at an amusement park. At the lochlz3 ll *4y09uijguu7 ation 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 speedl /m/8ljb;0hltawj 3ne ag) 0p in a counter- clockwise direction. 0n3a ;l wb l htmplga0)//j8ejConsider 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 contiav4l z)t1mo y3nuously 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 from3)a1 mz ltv4oy 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 movf e4u, ;nmuav0mrjg0 l*q j8n8es clockwise with constant speed around the vertical circle shown. Which arrow best indicates the direction of the object’l*8jq 8nr;muavj4 ng,0umef0 s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string cou7ci0n t)psftwwp yh0 :,q r07cnterclockwise in a horizontal circle above her head. The figure shows an outline of th y ftws t0)w7:c h0q7,cripp0ne 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 wit;wu14vy6zu n yh constant speed around 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 the car in traveling f 4zun wv61u;yyrom Wto X?

  08.35: Astronauts on the Moon perform an experiment with 3/1 8ky vc, +yxln:xget.ymbh a simple pendulum that is released from the horizontal position at rest. At the moment shown ib :v 8 3mheng,.tlkyyy+xc /x1n 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-li0 m9.: ikjzeo :ese6uc5g hv+fke object rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turnta9zv iuc 5eek+mg:e fhjo0.:s6ble's rotation 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 1. 0 kg oqv q u0ek j6i::e5/hxpuck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speede0oq x q:/vu6kj5eih : of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on the t30 im0l megp: g6yd78ztn hy;qb61iuend of an 80-cm string rotating at a constant rate of 4 times a second?l ihg qgm 0y 07te;p:n 668tb1uimd3zy

  09.24: A point mass moves along a horizontal circular path o psp78u60uhlgf radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass alu0pup s hg687s it moves?

  96.24: A 2.0-kg ball is attacw h3fse ned y4z)9go bez,5:w(hed to a 0.80 m string 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 balwe: n9h)4e yws5zez3god(f,bl during each revolution is:

  99.22: A child whirls a ball at the end of 0v0zms hun+o5.;,0gfzxm z cqa rope, in a uniform circular motion. Which of the following stah05cf+z.quv , z ms 00onzxm;gtements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a sk69 wa58d oto0gy.v rf/nt4sm 4iyy 1utring 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 maintai 5rs m0.1w oty uvtdi68g49yn/aof y4kn uniform circular motion would be

  07.22: A mass m is pulled outward until the string1frax 1 5hi 4 snm2:aq)5ydv/3kpvfoq 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 tf)oqa/p5 inqk 4dhfvy 15r1mxs3a2: vhe string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figuregq ,tbm+ddc,d1u /l0 p to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvatureudlt+dg /,0dc q,mbp1 R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a cvzo/e/zx b )uur:0j.g onstant 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 o.0ej zu )rvugx z/o/:bne 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 constant speed.yp)1lj)sbt jju 8+zq( The magnitude o(jb qp)j1lsztj+u8y ) f the net force on the sphere

  11.47: A simple pendulum of ;y 86.pgf-,k tojvyqtlength Lhasa 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 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 6j;y,k8t yo-t qp fvg.at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simple pendulum. The0bcks cs)32r5fyx zr; 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 str ;bscy f3r r2)cx0skz5ing (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 appli*t(osj etrc4 :ed 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 hco*t4jtr( e:s appens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connwuoe1 .pve5: c88 svzjected 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 nwvp .8vjeo8eu : s15czecessary 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 3*hv,b, tgtas..24 m/s in a vertically-oriented circle of radius .gsvth ba*,,t0.75 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 coi ukf,bl 5)pm *41/qnhv(2ij ma;vwssins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plambuv,;phn1j)2k5vl(*qw /s s4am ifine 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 about 9anm3v3p1 vbh7n sjj6the 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 and forms an angh1sbvnamp 7393v6 jjnle 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 figure. Twy*h qea pcdl(tl xg*8 b:n1z*c(u 5.xhe string to which the mass is.ulc*atge(ply x:zbq (c1n h8*w5x*d attached has a length 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 30.0 cm from a horizo:szvzgeo24xx:)e: izswt1 rd c92j*p ntal disk’s center. The disk starts to rotate from rest about its center with a v:xsz 4r9z2gz1pd sexj o)c:t ie2w:*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 mass M = 2.0 kg is attached a disk / n9zp-wv brccb*6;ltance R =1.75 m from the fixed centerk*c -9rv;plb 6c/wbn z 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, startwnwz;z.yobv24m6:zlay+z f/x :va8+pox d 4ying at the top, with initial speed 17.0 m/s. The object’s ;m8:++2 yow6yya/:zdaol n4 . fvb zxz4vxpz wspeed increases 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, startbh4 t5t7c ( atczc8*4 qsuof s/paj,o.ing at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an anglqsh(t t7c*a,tco 4u bs zao4c.pj/f58e 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 bls g lssl2/ /yh05of9kjock 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 ply2 5 /ojgsl0s/slh 9kface 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.