95.02: An object showv)b6i yc,ujinvix25v vh(e x0 -vze6+n in the accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the o+iieev60 5v2 vyvi)jx,- nvc6u(hxz bbject at the instant shown?

  05.31: A child is belted into a Ferris W gl9w x3r*5jisheel seat that rotates counterclockwise at constant speed at an amusement park. At the location sho rs3l5*x igwj9wn, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously m749 y8tq9lx8x7yz 8z hlubxcr2a/ hd goves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the partilzt 8c2h47 lg 9 xbrd8uy98hay/xxqz7 cle 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 continuoxxy4yh)3krlb 27.rs i(xs ,ptusly 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 aro(3 p.4x2y,bt sy x7rlx)khs irund the circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves c//dm f 1gbnqx3lockwise with constant speed around the vertical circle shown. Which arrow best indicates tx 3/mf n/qdgb1he direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the ag8n6 z),4 ikpsn z7otend 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 pass through the point labeled P in thk8 n) o,gt6pa nsz7i4ze 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 pathsb8 apb ht89d( as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car ib8ba d8 th9p(sn traveling from Wto X?

  08.35: Astronauts on the Moon perform ax(i-p eopb11fsum- 7d:c fd* gn experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in thepifp sm-c:df 17 -dx*goe(1bu 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 a rou2nvd.s ,wjs3v 8p.)i 0prlh fsgh 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 actinsj0s .lv3p8sid wh,n2)rp .fvg on the object?

  07.19: What net force is7 7s;) krco(s, bv/qqrq ypw4e necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionle 7/v s(bsye q kq;)7ocqw,rpr4ss surface with a speed of 2.0 m/s?

  05.03: What is the centripetal accel3 /ibt3(ai j o1ikmfy7eration of an object (mass = 50 g) on the endktim7ibai/jyo 3 (31 f of an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radiuy .ck zgt/m2q1p( wmh1:u cz0us 0.8m with a constant kinetic energy c y .tgz:k /cmuwp10h2q(u1 zmof 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 andon2 ; ;lv.cxzm whirled in a horizontal circle at a constant spe ;mc. vxnlo;z2ed 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 of a rope, in a uniform circular mx*gf 1x 6qya,etkmur k0c(9l+ otion. Which o0k cu,g1 ax( yq f+*ler9m6tkxf the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft))4r nywq ih 4k h()aut+jwqi( attaches a mass 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 F. If)a44qh uq )iww inj(k+y(hrt) 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 out* 95(gubp jdxjward until the string of length L to which it is attach5djub(9gpx*j ed 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 ofthe arc?

  94.15: A car is traveling omtfy-u4; i))9 xnskly2rbiu(n a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hillsnx sr)il4k2;tfuy( b9-m yu)i 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. Ad+w 0sdz7-r okt the very top of the hill, the shape of the road can be approximated as a circle with radius 0rs zw7d -k+do25 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 constant arka4)kl2m (kspeed. The magnitude of the net kk4ra2ml( ka) force on the sphere

  11.47: A simple pendulum of e5zsu 8fj-hdz6ve 9w5length Lhasa point mass M released 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 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)? fz h58v zsudjee- 95w6

  16.32: A mass connected to a string f:h zrak 8yot;y )f.wn24a5(d nwfl)giorms 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), and the net force acting on the mas f) t54k:w y;8grozw(.nhl2dia)ya nfs (F) when the mass swings through its lowest point?

  04.41: A centripetal c+h*figa 52xkbz* g.4or3kdi9r,v t kforce 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, bithf.*kgk rxk35d9zv2bgr i *, o+4ca ut 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 frictionless s+n g5/5jtt +ewp4y wir6b5rdfurface, 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 connected to it is now doubled to 2M. If the spring tr i6tng+45fj +5pb ewr/w5y dis 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 vertic8-a-nwj v1qdehvbxl:wjv +yo5q (* c9ally-orientejlqqc --nveahw:vv ox+dy(b * w58j91 d circle of radius 0.75 m. What 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 vs0k6e-x6yro 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 k60o y6rx ves-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 antbq+i)(2i nxc d moves about the string’s fixed en+i(b qtxi)cn 2d in a conical 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 i;x7d0,i p:r-yvvwxo b s in uniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 mxywrd:ix- ,7; bov0p v 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 re /w5;stfwehf1m6u,rest 30.0 cm from a horizontal disk’s center. The di6u1ee5hsm ;wtw /r f,fsk starts to rotate from rest about 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 with masscb+z ;qho9 7jjnx;lj * M = 2.0 kg is attached a distance R =1.75 m from the fixedj 9cbj+j n;z*h q7x;ol 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 initial sp0munl2u c 6aaa y,rc6* d1(gyqeed 17.0 m/s. The object’s speed increases uniformly until i mc*r c6 (,y1a0agy dnq62auult 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 :+assfu 5 8ectinitial speed 17.0uaft:e+8s5 s c 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 rests at the bottom ofnq ldq1:hb7g h jfv8:) a bucket. The bucket is spun in a vertical circle of rd1lh:f8hv7:qqb ) gjn adius 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.