95.02: An object shown in the accompanyinl.*tj (1-znalvfs ez. g figure moves in uniform circular motion. Which arrow best depicts the net force acting on *tl1. zjf e v(sz-.alnthe object at the instant shown?

  05.31: A child is belted into a Ferrisk -lsf l69/ -ksir)e b;anlo+b Wheel seat that rotates counterclockwise at constant speed at an amusement p ll-kl;/an)bofk-ri6+sb e9s ark. 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 y 5.lx y/oxkoz1dtt61 at constant speed in a counter- clockwise direction. Consider a timeo ydzxxy1/o16ktl5t. 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 continuo(c 3 m. (8dtmho 4n4leywhhg6susly 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. Point Q is exactly half-way around m c ohe3.l6n8(t(dymh4gw4sh 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)0*qa43 mzf5 w1v (zvj,+nbhpaoebc v the vertical circle shown. W*ow0 vzavqfb,zh 31m54)c e +vpn(b jahich arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connet. ;8(guom5wif k8k rxcted to the end of a string counterclockwise in a horizontal circle above her head. T;o(uiwr mk x8.tg8kf5he 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 should she let go of the string?

  15.23: A car moves with consta*xkj c zg vnf9cknao0u *w8:-/nt speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of /oaw 8*:kn nxf-cjcvkz*9g 0uthe following choices best 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 peqt90c39 ool csndulum that is released from the horizontal positionocc 3s0o9 tq9l 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 ob gjv)vv+gt3bj1oi, 5 bject 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 is5 1+i 3bj,)votj gvbvg 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 z l q0 .e*urz(gk*1d)fhh mt+qkg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed oh )th1z*dg+mu zq.q(*lrek0f f 2.0 m/s?

  05.03: What is the cen(2c9 g h;-sergvn,mf/upi7ootripetal acceleration of an object (mass = 50 g) on the end of an 80- r(pve7/of9h- gcsnmi 2g;u ,ocm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circulage/ e2psv 7 +f1fw2rblr path of radius 0.8m with a consta pf lsw7 febrgv+e212/nt 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 string and whirled in hfuinli86*6 j( bf6skt j5f9 na horizontal circle at a constant speed of 6.0 mb(966 sjntnu8fflii k6 5fhj */s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at +s.i6v bwxveijtq,6.the end of a rope, in a uniform circular motion. Which of thes bv6,vjx+i.i t.w6qe following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a kxzm 7t3js 23x5g+hh gstring 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 in327m35jxthkz s+ hgg x 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 lengthyrxxbx;0r iqphi3)x4* 68qt s L to which it is attached makes a 90- degree angle with the vertical. The mass is released from rest and swings *x;x it yq)r0i sx4 hr3x8bqp6through 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 a road in hilly terrain, sehi y *ieks9*2pe figure to the right. Assume the car has shi29* sei*kpypeed 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 oaq -4r5f hy/k6d *nvbhver a 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 as a circle with radius 25 m, as indicated in the figure. Which one of the following choices best represents thedh v4nkr6ba/-*hfq5 y magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical9d f9*3yqb8c 7r lahqp circle at constant speed. The magnitude of the net forfhr98cd yb39 la*p 7qqce on the sphere

  11.47: A simple pendulum of leng omunbedu4,i sq3l08 3th Lhasa point mass M released from rest from the horizontal 34o8,0nus3biq elm ud 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 at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simpg7l vf6wr) 1wjle 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 the mass swi6l 1w vj)wf7rgngs through its lowest point?

  04.41: A centripetal force9kff(f+kjj ua,j,sim: cp /c8/ mr6vb of 5.0 newtons is applied 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 t r/c8ijjf,9/kpam ksf cmb 6(j,u+ v:fhe frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connect1.hmhxhs0 f y3ed 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 connecsxy01.f mhh3 hted 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 mnj jr9gz /uq5 dm0q*t2ass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What */qznrugq0dmj9j 5t2 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 andY) are acdr w)6dq5 a+gt reston a horizontal disk rotating at a constant rate about an 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 5 rg+d6daq) cw$d_x=\frac{1}{2}d_x$. 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 th (z9 c 2b0gtrxf0bbv-ya)tsf( e string’s fixed end in a cobfrbtg(ac0(sxv 9zf ) y tb-20nical motion with 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 circular motion as shown:s2vwhj p8 pp7c)lyb1nj2u6 q in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms anuvw6q1j 8l2pnp2b)y:jh ps7c 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 30.02cjocjd5diq: xr( 9 hodv5( 9p cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant a9orjxd( d h9i5o5q:p c( cjv2dngular 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 att)ky c+0i- 4qk1foqmw8e0s lst ached 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 constant angular yf 0)qoi4+-s km0c e1qtks8wl 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 i61xxfwu:b f2 ngdd :2cn a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwdxncb :f2fdg2ux6 1: wise 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 gb*b+8x0a txxh,n2)s 7bhfpt9q dum2 circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an ang 2fxs,bxqt2 t n0*up8xa+)7mbhb gd9h le 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 bucket. Tm0bse 63r cm n:5-qyafhe bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highsc:yfq3e nmm0 5-b6raest point in its motion, it 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.