95.02: An object shown in the accovz s0wy4dk,lw f w,uv8of.c/5y/9wcm mpanying figure moves in uniform circular motion. Which arrow best depicts t /4wuf swlz ,,v8w59yvck cdm/ f0o.wyhe net force acting on the object at the instant shown?

  05.31: A child is be,3;xzs t hqcj)lted into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the ch ,h) xtsc3j;zqild by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant speedm 43gzdeva0 aj err*n)cbg09* in a counter- clockwise direction. Consider a time interval duringaz*cd0)agvg b9re jm *3ern 04 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 wfnxh , c/.12dbok k4:3jlphhpxk;y* moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circula2 c blxp.f hx,;4k 1y/kwh:dkpn3joh* r 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 verticx5o nxt+q6) 0m qatth*al circle shown. Which0+h*nmox tt) qa5tq6x arrow best indicates the direction 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 stringt2wn/j; wedy 4tq:khc a 4q99s counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from above the twirling mass. Ij9aq:neh;qw /4y c9 t 2stk4dwf 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 aroundhtipr 1ii/d3 ()ncad7 a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices bestiid(ir3 1h a7 d/tp)nc describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perav p1;4t a0yhltoy13y5c:o /qc+ ln amform an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagram with3l5nc yl + q1y tmt0:aao 4yovhp;1a/c $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) point-like objec7 4xlw 3y6oqam 88 khpbp7y2x,vh*vwfpq))x gt rests 2.0m from the center of a rough turnta) fx pwlav7hbhx 3x,2pq) 6yow4m8y*qv7kp g8ble 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 the object?

  07.19: What net force is necessary to keep amof5(ulqx /7l 3 m/xla 1. 0 kg puck moving in a circle of radius 0.5 m on a la//lmu3xm xqfo5 l(7horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accelxo4x- lh.-o;buht n 6hej8ft3eration of an object (mass = 50 g) on the end of an 80-cm string rotating at a ;ohnthx.-f6x 83 -obhuj let 4constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular patq3: v4a w2oi7,uc oivuh of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force, ouvq a7i:uoc w2v4i3 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 a horizontp,x su1,r.aatal circle at a constant speed of 6.0 m/s. See figure to the righ1 r.sa,xpta ,ut. 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 uniform circular mx91md(e9m7uos6god (r pl(yb otion. Whsrg( mo (m(lxe 19ou7pdybd69ich of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass-yhlyhx1nkx1w ))7 qrh0xwm , 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 w,x hy01)r mxq 7kyl)nw-x1hh 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 pul4sqcj;7k; baz5 cg o5mled outward until the string of length L to which it is attached makes a 90- degree angle with the vertical. The m akq54sc;5o;z jc bg7mass 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 a road in hilly terraine6 nz;ha9hah+ 8-zh6hh ez3ii, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver o9+e 8zaizh;hhhe6-3ian zh6hf the car is most likely to feel weightless:

  17.10: A 2000 kg car moves overe vi 3opxooj1q n-8;b0 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 appro3boexqj 8;1 0-noivpoximated as 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 circle at consd,1 v go6mwx m3i*zek7tant speed. The magnitude of the net force on thek w1v*xze mg ,iom63d7 sphere

  11.47: A simple pendulum of length Lhasa point mass M a.b 6i v klhx;x,;zoo*::vjffreleased 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 the l:bozk,jof vxx 6v;h.* ia;:f 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 connected5jc(1ejz.ihvq z jy:g bg 1*t2 to a string forms a 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 string (T), the gravitational force on the mass (W), eqgcj :1yj* i z( j21t5hzbg.vand the net force acting on the mass (F) when the mass swings through its lowest point?

  04.41: A centripetal /b lbz3z4lo yl 7j j;xet(6yu-force 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 ha 6zb l/jy7y34ot (b; ez-lljuxppens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a friction;9ewcnk 9l u c*/1nhsaless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm frk*9awhnn9;cs u/lc1 eom 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 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+xg9gy. pd9d/cvgy r pv*,bg5 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 5gg/v y g,db*gpd.xr+9p9 yvc the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal 7tln hx y16eg,disk rotating at a constant rate about an axis perpendicular to the plane of t,tny el hxg671he 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 string and moves about the strinqa(/o:i7amn hg’s fixed end in a conical motion with a c moi:/a(nah q7onstant 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 circulamp/o bqf w5ve*ej bk,(r4;q9xu cx:; qr motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an anglepf9 (oe*m;x ;4qe5:jq,r xwu bvbq/ ck 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 diskufdt:c u jlu*dxb6mh+(o)2.t ’s center. The disk starts to rotate from rest a6tujd*uu) dl(o 2mx.th+cb :f bout its 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 3a- nhx;y4sq gwith mass M = 2.0 kg is attached a distance R =1.75 m from the fixed ;n qh34-gasyx 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, wik4 i4x.klm zn:/mgsm+th initial speed 17.0 m/s. The object’s /x mls.:mn m4z+ k4ikgspeed 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, star tejldu5 h)1/f5d 3qbmting at the top, with initial speed 17.0 m/s. The object’s speed inud)h jf5t1bqed/l5m3 creases 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 rests at the bottom of a bucket. :h3,w3hopu sgr3s3es The bucket is spun in a vertical circle of radis33whue gp,o 3:srs3 hus 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.