95.02: An object shown in the accompanying figu)hf ahqu 1 r7-er 8r*pmxs2v8fre moves in uniform circular motion. Which arrow best depicts the net force acting on the object at th* ufqv1f)xseprh- 2 mar88r7he instant shown?

  05.31: A child is belted into a Ferris l;j0d/lvcfc. ch*i:v t o2e9s Wheel seat that rotates counterclockwise at constant speec l:2 c9vt j*;0lde/o. ficvshd at an 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 s;d- ,m manbu3 mdco79constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point ,9-uobd3m7ds;mcan m 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 pa/ mtr4zp:f4edr(4z4o k v+ w- mc:uwsfth at constant speed in a counter- clockwise direction. Consider a :oc44vrr:umz p/ -edt4f4wskm(f+wz 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 a4erhl (7zculxw y)*+7a3d8 ,mo qhx:h li3jwkround the vertical circle shown. Whice r:7 wwhl3(akl 7ohl,+ic3z )x4*yjxdhq 8 muh arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smallnd zg5p9 blxk2 *d1k/n.iawk 0 mass connected 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 point on the path shoung52k0 xpdwk/niz9 k1l *db .ald she let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shapxghett)bn:upp(2u 7 ou ;v0 env)is4)ed 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)tu pnu 2)et7biv;ep ):gvhn4s oxu0(rom Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulu y: d0z g /2cdtaus +6q5po+inx)j1etjm that is released from the horizontal position at rest. 5d q0/iap :+u1tjd zjse )xgnt6yo+c 2At 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 objecjc40 wjrr8rr sj x+(-pt 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 turntable is 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the fj-8+0pr4 jrcjxrsr( w orce of friction acting on the object?

  07.19: What net force is necessary to keep a *rc .)c-p9*e vm,t ee- iiog gg5rb7gq1. 0 kg puck moving in a circle of radius 0.5 m on a horizorgb7eptm -gr* , q9c*.e-ice5v )gogintal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accelerativ 8 ,oub6w,:/ (l wz4qsxpdznfv7 ks +.ndqv0oon of an object (mass = 50 g) on the end ofzv /s6wls(0 p8qw4xd u vfdq,+n. 7,konb vo:z an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m with zl25-j tiwj;a a constant kinetic energy of 128J. What is the magnitude of the net force actiwz2j;at lj i5-ng on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0ocwh1/ qld(zb 4wd 2rc z01k 4d4wjuusjm .k3(.80 m string and whirled in a horizontal circle at a constant speed of u/o j u4(0cmbwz4hkd3rjc .qwkl24 d1(d1 szw6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a tw19ry-o aln4o+g-or ball at the end of a rope, in a uniform circular motion. Which of the gy9on4orw-o 1-ar lt +following statements is NOT true?

  00.19: An astronaut in/vhdb 677rdlo5 x2f ln an orbiting space craft attaches a mass m to a string 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 maintain uniform circular mov/x l5f7drhdl b672notion would be

  07.22: A mass m is pulled outward until thhl /jz1 hvgb(+z9vw(u e 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 the tension in the strizgujzw vl1vh(9h +(b /ng when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrakrxy2xvf(+ r8qbln 6(in, see figure to the right. Assume the car has speed v and the t+yqkf 2 n6xxl( rvrb(8ops 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 auc iahgm+e5i h0u+0)j constant 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. W)huce0g a5ujhi m+0+ihich 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 constant speed. The m e-9e6+sbz11hlfkn cq agnitude of the net force on the sphe6lh9-ce zqk1s nf1e +bre

  11.47: A simple pendugtctj*/7+r1c pgwp y )3 4uwillum of length Lhasa point mass M released from rest from the horizontal position shown. In the absence of air re34iug7*t /ptgp1r )w cl+j wycsistance 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. The mass is re ao7;e9pd :coi(aaz ;sleased from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the tend 7e;csaa 9o;ozi:a( psion 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 applied to a rk,:n tii;62hg deoog 3ubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, b 2,o:tig6 hd3o;gi enkut 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 rest on a frictionlex23uz4s:ekg va;q9 1vf 9laviss 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 extendiv ;f 9v12xu:g3 zqsv9eal4ak ed 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 nj.iw,ev 1.nbuuungd o :f3o383c jl.kg mass with a constant speed of 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 thun.o uinl.gefoc3,b3 j8n :.u1 vd3 wje lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at ree r w**:ev +gp7 fxv,m/vluqn,zf3a /hston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distafn, v:xr+we7/qh lf*pm,v u/*z3eagvnce 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 the s sj37wlq baj11:jul4 vwk(t :ttring’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 tw q:w( t 11ku4vj s3lljb7j:aan 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 ny6 kjpfp8* )ain the figure. The string to wp8)*ay p 6njkfhich the mass is 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 horizontal disk’tuafx g6pjl(32 yo-d,s center. The disk starts to rotate from rest about its center(t36jgy2 ofp d,u-a xl 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 massobnza ,gm, 43zgj7h-md8 ) zpp 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 constant3bdogzmpa4m,- gj n 8,z)7z ph 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 speed o(h (t:jbkqc( 17.0 m/c(ojq( (b th:ks. The object’s speed 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, starting at the top, with initial speed 1j9 8i)rl-x.j vrz,(ychb ;if c7.0 m/s. The object’s speed increases uniformly until it has m vj8jir,x(y iccb) 9frh-;zl .oved 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 rests at the bottom of a wrni4 f-x5 z -f,u0z)taq*gmz 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 blwmfga)50uzx z,- ntq- zf*r4 iock 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.