95.02: An object shown in the accomp:nvui w) hw v2pnahf0/ os/8m6,g8mtu anying figure moves in uniform circular motion. Which arrowom/8s8 :it,/m 2nunwv) 60 uvhagwfhp best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris t l;zy.4oqe4- qicw*vd( p ya)pz5 k2nWheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted e i o;pw*zq)l5cqa.y-4z(4dp2vtk yn on the child by the seat and belt?

  08.14: A particle co/cpdakm.zws- ./t4 s/ 1 mzuwantinuously moves in a circular path at constant speed in a countzaw s/t..z pamsu1kmd 4w/c/-er- 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 velocity during this time interval?

  08.15: A particle continuously moves in a circular path at constant speep.nmm8 1 wf6n p 8x7k7zfdfsb3d in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from poi7 73p86z fw.mpmdbk nffsxn81nt 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 ve po28 0k-e(lslllcwk .rtical circle shown. Which arrow best indicates 20 lll( sk-c lep8kwo.the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smmrx, .fbuogr03wa6bf 3 + rv)lall mass connected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline .gr)bv3b ox r3 wlm,+fu6raf0 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 she let go of the string?

  15.23: A car moves with co guy9ys 3+)hm2zmou7snstant speed around a horseshoe-shaped path as shown with the arrows in the figure+)7oum3 gms92u hsyzy. 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 experiment with a simp+o7*q gju.fnm le pendulum that is released from the horizontal +o*umq n.7gjfposition 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 object rests 2.0m from theb 6cdvu( us p4n126h ; e9vzwge:vuz-z 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 fricti;2d 6h-u4 e zz6bv:pvunuzc e9vgw1s (on acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck mof7ca:+)dguhlr togs x4z2jye ; ,lk-,ving in a circle of radius 0.5 m on a horizontal frilz 7to adxlhg ur+ y- sf,e2:;),4gjckctionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an ob eeg7-9eybe .aject (mass = 50 g) on the end of an 80-cm string rotating at a constgyaeeee-9b7 . ant rate of 4 times a second?

  09.24: A point mass moves along a hor ;apu.e:xx2d yizontal circular path of radius 0.8m with a constaxde;:2uyp x.a nt kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attachek(+jcnkzr1,-m ,r fhwd to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each r,k c1r+r-hn (,kfmw zjevolution is:

  99.22: A child whirls a ball at the end of a rophnhnu3;f48wy sxcfg1s xp 1 0.e, in a uniform circular motion. Whipf 1 n1hh3csus .xw48f ;g0yxnch of the following statements is NOT true?

  00.19: An astronaut in an obt are*mn9mb:p+w2i ;rbiting 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 tensbnrpi ;+m :ae9m bt*2wion 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 stringe wo()kuse )a; of length L to which it is attached makes a 90- degree angle with the vertiwe); ko)ause (cal. 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 on a road in hilly qd.d92bbie f9 n3k bv5terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have b25q in3kdvbde.b99 f 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 a4k0ueil )p4r zt 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 c lui ez0k4pr4)ircle 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. The ma/x ,s:*gt uwjegnitude of the net force on thetx*j,gwu:se/ sphere

  11.47: A simple pendulum of lengdf p1 8p,xhyx/dteq1y (p1a3 yth 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 (ten xq1 1p1t3,fx dy (pdyy8ah/pesion), 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 form ;;:nm.riy1bnpca sbq- :x nu;s 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 t;c n;-unsyb;nxb.:a:pq 1rmi he 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 of 5.0 newcnq *d8gbv5/ u z+ydry+,o27mj dz-yttons 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 happens to the speed v, and theuzgz-qdm,c j7t b5ny8 2yd ++ov/ *dyr frequency f, of the stopper?

  05.28: A mass, M, is at rest on atr9,,yvyzs p) frictionless surface, 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 spyrzvs)y , t,9pring 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 consoq 330c.mtlputant 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 the. omcp3lq 03ut lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontab 6kw:g7/*5ksyy xvgqt3kyu (l disk rotating at a constant rate about an axis perpendicular to the plane of the disk and tx7b kyk5ygt 36k/ *qyv (u:wgshrough 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 7 zsiqpk,f138-fwe hrto the end of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has afq is,-e1pr3w7f8z h k 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 circua0mkdaghqs0 tcvk5jh zwpq .9 98e1q.. -*feilar 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 anglef.9qm .kjvt 18q0aseweka q 5pih*.h-cd9zg 0 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 horiz)0-bw xv0zwxps arv6azl:,d- w2 y pt1ontal disk’s center. The disk starts to rotate from rest about its center with a constant angular acceleration -wx0p6p ,-r2y)wtw b v1 saad0z:vzl xof $4.50 rad/s^{2}$ . 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 atta kc2,rv+2 si(mijri 8gy;3,q p/rkrmfched a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating frsimqjv,r+rm3 p 2i2gr,k/kfi (c 8 ;yrom 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 initiautfgn5j3 w .2gl speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an au 3gg.jft n25wngle 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, stg h8+y*wbh z1*vvdc- harting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countyz*b*c v+18hhg vhw-derclockwise 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.u 8u0;jf bkpu+ 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 fas;8ukj fp uu0+bt 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.