95.02: An object shown in the accompanying figure ddth*ur*ro b4l k246oll 9v s;moves in uniform circular motion. Which arrow best depicts sulblo r*2;od49d kt*4hr l6vthe net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterc*m1gh j+v-;b/gycmp ti,wkg;lockwise at constant speed at at*w 1/bim;ghpc,v;- +k gmgjyn 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 conm hih)6522fyd h 6gl9mmdi,jdstant speed in a co, mhh 6l2 i9y)2midmdh d65jgfunter- 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 velocity during this time interval?

  08.15: A particle continuously moves in a circular path at constant speb4 0kj- uofged(reg2 3ed in a counter- clockwise directionfgjb3-(ge4 do2 k0er u. 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 speedlckl +l77hx(c ku r6)0;bdauj around the vertical circle shown. Which arrow best inc dkl+0l(ha)u b7r7u;k6x j lcdicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass c 4joc sw8wra *dmw ti:,4vpk67onnected 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 8 sr *waojp,47c wwm64kv d:tipass 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 /w0 yox-sp(9mg+ u-n5rjz9xa8o g xlmspeed 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 c-mnx /o xs0p-yo9gwmur58gal9(jz+ xar in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with ;7gp.br yt6ba m 0n4yya simple pendulum that is released from tht;4 pa0g.n by ym6ybr7e horizontal position 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 object rests 2.0m from the cho2avfy sw9/a0str( m;d 8ky)enter 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, whildh);a9( mrwkat0yvs2 yo / f8se 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 keepw4hb5te- -7h uk:ey8 s6hz lfp a 1. 0 kg puck moving in a circle of e 4z86 -phh:fetbws u- 5khy7lradius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accelerationiq g3m)0 lj9zzyj-o.p e fu/)d rhe3i4 of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a secon i/orq m- fpz04 l3.u39ged)jihj) ezyd?

  09.24: A point mass moves alodo0iow (i (uk9ng a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the k9 wo0o(d (iiunet force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whfc(8tkm 8 (2hx4bc zbrirled in a horizontal circle at a constant speed of 6.0 m/ c4rcb2mb8k(f h8(tx zs. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at thegsb/,b c uw,0yf ,dfd4 end of a rope, in a uniform circular motion. Which of the follocuwsy0f /g,d bbdf ,4,wing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a w f;mja6el45 q/5hnklstring and whirls it around in uniform circular mo lj5k;4w5hle /6a fqnmtion. 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 pull;r8ar+.ix/pony fhlceh(; :,cb ,ys eed outward until the 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 string when the mass swings through the bottom o:bxilreoacf,eh+y c/h 8ys n p;;,.(rfthe arc?

  94.15: A car is traveling on a road in hilly te ac7/dw2z3l)ja m pwp)rrain, see figure to the right. Assume the car has speed v and the tops and bottoms 2dcz)pa /w l7ma)jw3pof 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 a constant speed of 12.0 m/s. At the qg3n peddc5v87-o8h cvery top of the hill, the shape of the road can be approximated as a circle with radius 25 m, as indicated in the figu 8de h3vg7 5nocdq-8pcre. 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*;rl 7 a reyxv) n;z 20y.dd.xcpt-soz is moving in a vertical circle at constant speed. The magnitude of the net force on the szry l;e .*v y)0tz ndoa.7xcx2;d p-rsphere

  11.47: A simple pendulum of length Lhasa point mass M releasek+ 1p:vj. gl)muwqq kkg 0,g4ed 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 the4v0 ukkqg.lmw j1+ g,:)qpegk 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 aixfu*;m fq; .5g)6aag /svrj n simple 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 5fra.j; ;q)*i uaxs6nvg mg/f 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 gpux)b h ( i;y8)vo6m)y9zvd aecm51c 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 the frequency f, of the stoppev5 9eh)i cybod6a zmpv1)gcx;u)( ym8r?

  05.28: A mass, M, is at rest on a egcr)p)1 e*5dyg6bn hfrictionless 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 the5 e6)ehrd)b *pnc1ggy mass connected 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 ma9db i 6s3cfri9ss 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 oni93 9cdir6sbf the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horf*92d)pbq1fc6z hj sgizontal disk rotating at a constant r9jqbc)zpf*6d 1 2gfshate 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 $d_x=\frac{1}{2}d_x$. 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 strinor35y;w0vec 9lml6l iw3 4 luzg and moves about the string’s fixed end in a conical motion with a constant speed ;me 4l093c56lz 3w o yrvlwliuof 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 sho5 xkc/ 0u:avduwn in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of ku:/ux 5vd0 ac$θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g is at rp wh7ojthl0-0lmv3 d7 est 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular accel0hvl3mlj7htow 0p -d7eration 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 distance R =1.75 m f59bxl6lfvu ff(ys b59rom the fixed center of a disk as shown in the figure. The disk starts rotating from ru f5fx9(f y6l lb5bv9sest 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, startx dlj nm0c*fsjuo)66dwcf820ing at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until 0cx l *s2 wd0nf) f6ju8cmdjo6it 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 i r/vb81kbpp (ynz99v 17.0 m/s. The object’s speed increases uniform/8 ykbiv brpzn 991(pvly 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 rests at the bottom of a bucket. The bucket is spunpp9 siu l0r: p*1ord4l i*l9p1doippr0:4 url sn 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 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.