95.02: An object shown in the accompanying figure moves in uniform *rf6g*ziksxio3,l ekeaj, (5 2osg)k circular motion. Which arrow best depicts the net force acting on the object at the instant shoigej )szk* a 25 f(,6kogls 3i,kxo*rewn?

  05.31: A child is belted into a Ferris Wheel s3 duybd w46akok64d r9eat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?6dk39dkr4boyu4d6a w

  08.14: A particle continuously movesj +zb+df(/vw 3j*iws,aks9s p in a circular path at constant speed in a counter- clockwise dirf,ia+b/sv(3 s+p9 jwjw k z*sdection. 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 continuot,ty:ogzoe (*/kqb z6usly moves in a circular path at constant speed in a coun gtbez/6to* (ky,q :zoter- 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 acceleration during this time interval?

  15.07: An object moves r9o,mv;zo;w (b- hr zwclockwise with constant speed around the vertical circle shown. Whi9(or z ww;or-hv,b z;mch arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls35r.ngr3 hx.f 1 v5znawisa) e a small mass connected 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 giraxz)v nw1gn r .ieas r.355hf3l 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 around a horseshoe-shaped path as shown qkc167fzf9m6mujx zek 9 h,glm7 ./gj with the arrows in the figure. Which one 1 6qmh9x76uf/j ,zkj9 cg kzglm.e7mf 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 Mod h r3)-sh0 o;xei+be.ppgc+-zye j l)on perform an experiment with a simple pendulum that is released from the horizontal position at rest. Ajzhp- pe)d;goi 3e bsle r0y+h-+c.)xt 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 k p obzf(66i(tig) point-like 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(f(6zi i6ob tp.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 kg puck moving 8-:ame(k p;itlyc s7zin a circle of radiia7 psl k:zt-e(yc8;mus 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (masl-l.ajm ruazl:9msf(-;;ay w jjwd ok 3x*7x4s = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a second?*al s-majzm( 3koy fawl4-x:7wj9 ;;x j .urdl

  09.24: A point mass moves ozu zuz7it3 5,along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on th uzozu,7t35 ize mass as it moves?

  96.24: A 2.0-kg ballf*r3qb ad4nk)n)px i 8: ax(ym is attached to a 0.80 m string and whirled in a horizontal circle at a constant sd8an * 4mxpx ())3 aqf:nrbykipeed 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 circulaij loa u+oz1*j(*gep/)g-k 0,i v xmker motion. Which omkia)1zj*(ju pg/gkolo- evex *i ,+0f the following statements is NOT true?

  00.19: An astronaut iwjnz.-;y1dj crax o-5 n an orbiting space craft 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 the mass, radius, and speed were all to double the t-xrjdz;ync.1ow-5j a ension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward u)z7 t0ttvk b)ontil 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 tenk7t)zt0b)ot vsion 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. z0*pkez zg-zv8 ot7 t8Assumeoe8gtz0k 7 z8 -zp*vtz the car has speed 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 over a hill ato 7ao(obi 6b( wvsklun2387xw a constant speed of 12.0 m/s. At the very ox w6bk7w nv7 (o2i8s3lbuo( atop 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 the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle(imcu:u0hae9 49c (xfq8pw/oup ps :g at constant speed. The magnitude of the f(9m ocp cqi0a 9euws4:pp8uh(/x: ugnet force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M releaya+ q+()7tfw( dw1) hpvvd kv/ alegg4sed 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 y4vvt ww7g(v/hdle+f(+ kp a)q1 ga)dthe 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. Thenh:6 rh-ssxtww7,ws y/js. j8 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 /hwx87,sssn:w.-6 s jjyhtwr(F) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is ap.cp8k kc0v+z qplied to a rubber stopper moving at a constant s0pckzkc+v . 8qpeed 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 stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected xh 2vc;uoxt2mhz(62esl)5)sbq e y 1zto 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 is extended back 30 cm from equilibrium, what is the necessary f()xhz2z1bl)2 e hy;5vosq6 mcxus2t e orce applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg ma.ghza 14a.qog-g-4e hri zg*rss with a constant speed of 3.24 m/s in a vertically-oriented circ g h-4rza1gge4a*..ir- oh zgqle 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) aresp ,w+5u yjd+3)p cysl at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. Th++c5w s jpdup3l)yy,se 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 moveswb (j(ka *+altgyb. bg /z6z;h about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a length obj;*tg +hb yw(6 akzgb l/(za.f 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 a+xzun .kay8v ,e9q1iqs shown in the figure. The string to which then q.1x9azv8i +,eqyuk mass is attached 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.o84d hkm/y+vfl.ne1a0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center w48vyhk+af.e /on d1mlith 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 mass M = 2.0 kg is attachedow n6y3l tfnfyw3 el0g;- b2btgz- ;/k a distance R =1.75 m from the fixed center of a disk as shown in the figure. tgwl-k y-b ;0fn / glb;tz2en3wo6y3f 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 circla05s q d1qos09mza2v)pyy k6k e, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved couzv90yad oq p)kak 6 m0s2s51qynterclockwise 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 ht c8zvx/)*bl 17.0 m/s. The object’s speed increases uniformly until it has moved cou)*t blxv/8zhc nterclockwise 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 bottovib--( ykyx/bm of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucibv-/-xyb y(k ket 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.