95.02: An object shown in t wvm;o y ac1+a4(sb0izhe accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the objec ov0bay s+aw4;ci(1 mzt at the instant shown?

  05.31: A child is belted into a Ferrk jjl91b-2g b7zyrz:kis Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the locatio2:1jbjy9rz zlk-kg7 bn shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle cont bz2cka78h1a+ j1dk ioinuously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the pd k 18+j7c aab1ihozk2article 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 continuously mov5x g 3rdzva;r.es in a circular path at constant speed in a counter- clor5 adg zv3;rx.ckwise 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 circl 8o u: 68*3noeg9sg4xwztbqzce shown. Which arrow best indicates the dir nz84swuob 93:qoc*8g x6zg teection of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string countercloctrg(qc1; zc byo28m5 wkwise in a horizontal circle above her head. The figure shows an outline of the mass’s path cy qtg25; bm1(wcz 8ro 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 constant speed around a horseshoe-shaped path as shownm-p 8tg+b07yv b xequ+ with the arrows in the figure. Which one of the following choices best describes the ve7uxtm qb0yb 8gp+-+ direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perfo-*tt5c4ge p+mx1xe izrm an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown inc4ix zt +g xet5e*mp-1 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 center of ao,tu ;aoc/ty2 rough turntable as the tuo,yt u2/t ;oacrntable 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 force of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0 1 +jbf1z c:/fyabqa0a kg puck moving in a circle of radius 0.5 m on a horizontal frictionf0ba 1fz 1+b:/aacjq yless surface with a speed of 2.0 m/s?

  05.03: What is the centri* dgb cy4oeht 3.w;92x,im krypetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rota y*3y,h9rx o2eb4gm tdwik;.c ting at a constant rate of 4 times a second?

  09.24: A point mass m;k0 ufbr,0oc+nw kf 0y,whai; oves along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What wok rc, ak0f0 ;;hin0,wfb+uy 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 sz ,q+xa m/rp-btring and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the righqb,+p zmra/x- t. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a unif0+ox 74qp ku,e ijmzv7ezj5v: orm circular motion. Which of the following st kjm+:,zjz 0qeu 7pev i5vo7x4atements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches 0 kvv ak3;4pj2 ojucylz,z8d/ a mass m to a string and whirls it ark2oa /yzjvc; 4ul3djpz8v,0 kound 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 motion would be

  07.22: A mass m is pulled outward until the string of length Ldr ab7zzs tp:je(v936 to which it is attached makes a 90- dj9b(r:3vdz tz s ap6e7egree angle with the vertical. The mass is released from rest 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 traveling on afo *ty/c,n 0vx road in hilly terrain, see figure to the right. Assume the car has speed v and the ncv/ y,* xotf0tops 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 an d4u, grcaq 7:q2aviu3r+ i6a hill at a constant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be approximated as2ivg7 3aiaru cqda4 u6r,:q n+ 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 by the road on the car?

  97.13: A small sphere is moving in a vertical circlemkf. jukuc7 u6f318x x at constant speed. The magnitude of the net force on t8mffuuj6x 13c7kk xu. he sphere

  11.47: A simple pendulum of length Lhasa point mass M released fruy +r -cwfd/d.om 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, adcy/f.r+ud- w nd 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 s7c u.aj, dwx3f soue1.h mig6vy2b2 (qimple 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 the mass (F) when 6u.jqcs ebu 27 hdg ,f23m(1iowxya .vthe mass swings through its lowest point?

  04.41: A centripetal force of 5v.k n,lnchkhsj ocr 19)yw.m9 ybd7-ezp/ 0r6.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontjzkyc/k9.6s0r womp1c,9 ln)vdb erynh7h. -al 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 rest on a fr h:3p2og1hm3x;o+ o q4p+ 1 hbvjesewyictionless 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 cop; xmy 3h o1pg 1eh2we3o:hojb++sq4vnnected 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 3.24 m/s in a vertic u-h +vvdq/k-ually-oriented circle of radius 0.75 m. What is the net force acting on th-k-uv+du hv/q e mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston aqz -sj**igg 3a: hr-p3-1 ;mzmhzdetki11ufs horizontal disk rotating at a constant rate about an axis perpendicular to the planeemgps;31kiz *-r z-jtq1m g:-hi*d hs1z fua3 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 conyttgb*ie5) l *6-qbr6u9iaj7 sh dml0 nected to the end of string and moves about the string’s fixed end in a conical motion with y m5t-i0*btljasr)uq6 ie69g* 7bhdl a constant 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 c+;) z:bmxvx s0zu y3xlircular motion as shown in the figure. The string to which the mass isz) v xx+ zmy;0s3u:xlb 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 h+:e rts9 xtn8borizontal disk’s center. The disk starts to rotate from rest about ir: n etstb89x+ts 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 with mass M = 2xhr:n n*57 cc2c(ieua .0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. Th*2cr hni n5ucc:7(ea xe 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, startiv bxtz/3 t96dyng at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has movtytz3x 6bv9d /ed 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 b 6xlk 9hi/:rda circle, starting at the top, with initial speed 17.0 :x6klihb9r/d m/s. 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 time for this motion?

  17.38: A small 2.0 kg block rests32j/)qvc7db8 l 0ntvrmxpk h1 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 1/t 2m3bv7chrpvk0 nj8dx )l qfast 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.