95.02: An object shown in the accompanying figure moves (6udin, :fxf)3qd 2br)pjs/ji gv i7yin uniform circular motion. Which arrow best depicts the net force acting on the object at the instant qib(: jid2p rg)ysu /3nd6f7i)f, vjx shown?

  05.31: A child is belted into a Ferris Wheel seat that rotate k :mnc:zdgcd4(6r(qrs counterclockwise at constant speed at an amusement park. At the location shown, which direction:r d6d k(4qzn(cc:gmr best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path *wzmjxj)zg:hu/) msbc p)1u / 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 around the circle from Point uwp x/g) h*bj)m/ujzm1:) czsP.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves is: g50j4 ps/kwv vrk0an 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 e5w4/0apsvk k :v0rj gsxactly 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 co+ m04:dvbz1 +eguyvycnstant speed around the vertical circle shown. Which arrow best indicates the dire1+ ye +0b4:uvgd zmycvction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end 5me-ggt+rt l l 8:.hfo r+ut)uof 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 +lrhoglem)-8:. +ut t5t furg 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 around a horseshoe-shapey jei06ek- d6 zf,nd,gvas .j1 ;pjva(d path as shown with the arrows in the figure. Which one of the following choices best describes t 6.,(ayg;evispf,ze6dj-v kjnd1aj0he direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulu pt)elsc:4buc3c2a b (m that is released frocbb(3ecc sal 4tp 2u):m the 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 ob7uob8 ts9*va 0dxk8, (asnv eqject rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 s at bk e*sd(7,8vq9v0uas8noxeconds. 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 a 1. 0 kg puck movz6p -(pl,t h xtmc4oz*ing in a circle of radius 0.5 m on a horizon6cz4t*x lphm, o- t(zptal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on the enf9tr3sb 7he h)d of an 80-cm string rotating at a constant rate of 4 times a second7hh)te 93s rbf?

  09.24: A point mass moves along a horizontal circular path of radig 6xqny23 ardb3pd( y0us 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force act2( nrbygx36 p0d3adqying 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 how2m3 o9fxty0yx:i (fc *(hka wrizontal circle at a constant speed of 6.0 m/s. See figure to the ri f2w9a(xco(0 * yiwyk3:hft mxght. 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 unifoem+0 +gjz 7bhvidv:b g/)a kg;rm circular motion. Which of the following statements ak h0 veb i+bj)7v;dggzg/m:+ is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a3(j xgfhsa7nd6z4n6g mass m to a string and whirls it around in uniform ch (ngf4j g3nza 67dxs6ircular 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 tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the stri l91x 2) y/;sjhjihxtz6hps+ong 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 ti o6jhh1j s9+2/ l;xhpst yzx)he tension in the string when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terra)uob,((niwla qv z7v8in, 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 of the car is most likely to feel weightlessol8a(zinv)q 7 bu( ,vw:

  17.10: A 2000 kg car pzv o1.j5ctkzf*: ha3moves over a hill at a constant speed of 12.0 m/s. At the very tz5pafvzto :c *k3hj .1op 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 at constant speed. Thw iunf (hwe38y)kjt6 4e magnitude of titywf(u hjnk3)8 6e4whe net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M r.h:lpblz-:lp eleased 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 gravitatplh l:plbz:- .ional 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 si1 :nhi- f/)v8nvdky fmmple 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 mass (F) when the mass swings through its lowi hf/8mn1-vykd:v)fn est point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber syw d3s45 o)vthtopper 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 t35o ) dws4hvythe frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an id+ j 9mfbsoe7 oh-wez.-eal 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 fzb+-7 e- j.ohemo 9fsworce. 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 l v2bwinn(g-z5;db 9da 4.0 kg mass with a constant speed of 3.24 m/s in a vertically-orient vz-b bn9wd(2glid5; ned 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 (labncn s-t2ky +x+2jhg v)eled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of +h-kjy) 2 nnt2s+vxgc 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 string andyv9re lic .nem0 mtit/g k4vv)-*q zri .:h1+m moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has ac9r.-z0 :4v.e )h*kmtm ignrviqvt/ielmy + 1 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 shown z14w:iu .npm7 gc2gns-c. xr din the figure. The str2z dgrcm: .-gnixpsw47 nc.u1ing to which the 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 30.0 cm fro 1sn ixj0b)j/sm 47verm a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular ac)4nvxj 0si sm be/7r1jceleration 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 from4lt(m wy (hfaw:ih 7;r the fixed center of( yt 4a7wfh; whmir(:l 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 speed 17.x,xnu foyfo/w(1suk(v95 y+ (d5chum 0 m/s. The object’s speed increases uniforu u5y9,h(( s1(wnvo xmc5yfu/+dfk oxmly 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 7j;8rb4h6 rm yy8q 6qk)l idema circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throhrlmm6r) 6k yey8;dqbij7q4 8ugh 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 bu1cp1jm6tu.k xn ;.qstcket. 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 fast enough for thu;kp.11t nts.qxj c6me 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.