95.02: An object shown in the accompanyinati (+q 27c+jr r+jvtrkg1 w,dg figure moves in uniform circular motion. Which arrow best depicts the nrgr(2+1+idtk j atj rcvq+,w7 et force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat 56 4yssh1tdby that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total fh51 s tby4d6ysorce exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant spez.uqh8 zfj tj(9j.i, ved 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 it uzqzhj8j,9vf .j(. the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously move x 3f*so + s)pvokvhx gt+*t46t2sb-sjs in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this ci so)sxt- x*jstkbg+*t+ps6oh3fv 42v rcular 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 circle 5z zxx95+g:v q89ax.ea7 buap xl3z ovshown. Which arrow best indicates the direction of the px5xg8z9e o9za.zul+ xa xqa 7b:53vvobject’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string counterclo jak.e8dq(6- es veu(lckwise 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 should sejsak6 d l. 8(ve(uqe-he let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped ls m r.,t(9,fb: k7zvbn8ajng path as shown with the arrows in the figurl z, : snbj(9gt,nmv8fa b7.rke. Which one of the 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 ex1m;/bhd ldl/q .e;r daperiment with a simple pendulum that is released from the horizontal position at rest. At deq amd ld1//.l;;rbhthe 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-+yx gcmce2vf:/( 2bzolike object 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 force of friction acting on thg2(ex c+ m/fvyc:o bz2e object?

  07.19: What net force is necessary to keep a 1. 0 kg puck mu pk0p:cd 0u3)z7ygmhcp;w y5 m. 6vdfoving in a circle of radius 0.5 m on a horizontal frictionless sydy;p36m .vcwckh 5pug:p 0z7d)mu0 f urface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleratikgi. l j*h j+;.cw9giuon of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times au w* c.j9.g+lgjhii ;k second?

  09.24: A point mass moves along a y7 pfj6zsc ql7o11iq2 v 9u/dshorizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude ofl17yc61z odsuqp /iq9sj7 fv2 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 4u3fr2nz jd0cu i0yc3and whirled in a horizontal circle at a constantru023 0dn fj ycc3u4zi speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of0 hs-i*u8y.rkph hci2 a rope, in a uniform circular motion. Which of the folhrsc-i 0 *.hph 82yukilowing statements is NOT true?

  00.19: An astronaut in an orbiting space craft as +5fc 3nao9yhpg8ch *ttaches a mass m to a string and whirls it around in uniform circular motion. The radius of theh8sp3y h+a5ccfo *9n g 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 sqwdd.i(51 f usq9slu7 tring 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 s5l(7 9qidu sdw1uf.q 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, see figure to the right. At*3lw qhnl+:nih x -jktkn*,ub66 a-zssume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of the c 3n* j6lwnuaqknztt,i+hl 6b*h:k --xar is most likely to feel weightless:

  17.10: A 2000 kg car moves bva)+ dgk/ s3ba3*iz tover 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 folv b*3gab/sa)zdkt i3+lowing 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 yk;rek r1crz, : dk+z(zd) c k.:owln/vertical circle at constant speed. The magnitude of the net frk nrcw:oy;e )c+d rk. zz/k,zkd1(l:orce on the sphere

  11.47: A simple pendulum of length Lhasa point mass M releasedbm 2v)a k).vdy 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 (t ba vy).m2)vkdension), 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 relexv e pt(ibz )2o+kzql*,hqs:3ased from rest and undergoes simple harmonic motion. qxpsle (bt 2*vhz :oi,3 q)zk+ 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 swings through its lowest point?

  04.41: A centripetal force oso +h)rl.,*,z xissk qf 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If zshlo.is+)r, *qskx,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 frictqz8gf..-k1 yl,s mvx lionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and holds it at this lo..lx l8vk q,1yg-szmfcation 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 necessary force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass wab1l+;r sc;lfc;vqxp:bh42cith 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 2;r1achbvl;cp+c;ql4bs x f :at the lowest point of the circle?

  14.23:Two small idenscn 8w/0h45 9f urgjnvtical coins (labeled X andY) are at 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 cenvh0f4 ng 9c8wjn5s/ruter 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 congx+-ch tc1-w;wx2drysdvj)8p u v g .9nected to the end of string and moves about the string’s fixed end in a conical motion with a constant spex+c- ygu.w2;9v)ph dr -w 1vjsdtx8cged 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 i zpzl 3f/ dg+72zn9opzs in uniform circular motion as shown in the figure. The string to which the mass is a3no z9 zpl7+z gp/fdz2ttached 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 disj(dc3g-e 2lp1hynn mvee4 c05k’s center. The disk starts to rotate from rest about its center with a constant angular acceleration of4 c5(p2lyjghdn mec3-ne0v 1e $4.50 rad/s^{2}$ . 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 mas3wl haeqq.b4t1 3j4zn s M = 2.0 kg is attached a distance R =1.75 m from the fixe ael.h qtn43j31bqw4zd center 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, starting at the top, with ini)tttonl7u-n(p , .odztial speed 17.0 m/s. The object’s speed increases uniformly un(7 -t.tnplduo)to, nztil 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 ini)ps4zru6 xb u+cnk28d 1d8 gdk2ex+jutial speed 17.0 m/s. The object’s speed increases uniformly untild +u+n d 81x4kjcp6kzegd82u 2xs)r ub 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 thegw+ya:/ect /)f gqbl*h8 e) ltedns; n9ym4.j 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 ft.):h4eqe)mwc a ;+n8fd jyl *9lte gbns //gyast 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.