95.02: An object shown in t 7 b 4qhqj3c8h.kphwy5 t8zhs)he accompanying figure moves in uniform circular motion. h).c qk t8h3854hs 7pybwzhjqWhich arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterod1i b)4/ litbclockwise at constant speed at an amusement park. At the location shown, which direction best represents1ibdti/4 lo b) the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path yl( :kzg.a1z uat constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circulaak1guy (:. zlzr 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 speesx53g /,rhnb 7zw)k ofd in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path froh,b3swn 7 xkf5g roz/)m 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 speedeqcb.g sv30mo-bht. 4 around the vertical circle shown. Which arrow best indicates the direction of the 0thvcmg4 3.-eb b.oq sobject’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the8w1:ivp;v .z rv-jys4b 5zxy p end of a string counterclockwise in a horizontal circle above her head. The figure vb ;pz rjiy wp4v y51vs-x.z:8shows 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 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-shapede, zw*g ums(8mapq, ,w path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average,gsamz 8equ,wm*(,wp acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pl3sl820 (yihrb q6a izendulum that is released from the horiz i0zqh 86(lbyrs2a 3ilontal 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 object rests 2.0m from the p+ .h2t*xu 0 r+.zr9dntqi rohcenter of a rough turntable as the turntable rotates. The period of dhz + tp0n oq2rtx+.r9irh*u.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 a 1. 0 kg puck moving7 er.ubz*,s-0a6 a 83e zpo bhitw8axw8m-ghl in a circle of hm7su83- b8.8aaxz-0tw*bgo la, 6e irwpzheradius 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 (mass = 50 ( i5n0ec ay..r;bmfxcg) on the end of an 80-cm string rotating at a constant rate obym0(f.n; er5. axicc f 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radiuxwwx c/tk v0)-d;, m bvur,pf2s 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net f2vmvw dp/,u -rtcw ;fkx0,x)b orce acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and ,rfg z(c4bc o0b6b:hawhirled 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 :0g4bbcaohf ( 6brc,z revolution is:

  99.22: A child whirl 90/tj2hwwjg cnfr7r)6 bk6m4v eucfbl: t20ds a ball at the end of a rope, in a uniform circular motion. Whij0vmw/ 6r6) wc2 efj ncbh2:7 kr40utg9bdtlfch of the following statements is NOT true?

  00.19: An astronaut in an orbitinz,qm;4 ihrw/ cg space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of the circle is r,4/mq czhw i;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 4(ce )6pz3fzyfj8a tg 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 tensioa)48tf zzjc(fp 3gye 6n 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 fige3yn7tce wg5j6/jt) ud(:hjsure 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 mos ge:6yj/h (t7ntuw3 jc5j)sdet likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a cmyy y(zbj7pq (b7k1n :9 5pvgnonstant speed of 12.0 m/s. At the very top p(p7 k bq5y9n7(1:jvy bnym zgof 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 cons;*eyo waa:fpi(a c.49ibkj 3n tant speed. The magnitb 3o:akyeapcni .;j fw(a*i 94ude of the net force on the sphere

  11.47: A simple pendulum of lebhmf ;jz/ 5/ajngth 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 magnitudeb/z5mjjf a/h; 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)?

  16.32: A mass connected to a string forms a simple pendulum. The manh uzqg) (a/o/sb/c62t xla t8ss is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the tension in the s6oq a ts /z2a/u8c/)th( nxbgltring (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 newtons is applied to a cao6wm(2e)yx 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 the frequency f, of the stooa2 (xmewc )y6pper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an ideal )wlvm)6e84 rl --jtsa lf8yme 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 ivm8yr 4) l8 -t-l)wam6lsefje s 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 spe (iwpr, ;4h8otp/fdmv ed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force actird ,4mip8 f/pvho ;wt(ng on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coip;z lvvi5*jmci cfm-)/6sz -jwdb1 1fns (labeled X andY) are at reston a horizontal disk 1jjl5i-mbp v)cw/mf ds1ci *; zv6zf -rotating at a constant rate about an axis perpendicular to the plane of 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 connecqc* +wm,rjx:v5ts2x mted to the end of string and moves about the string’s fixed end in a conical motion with a constant speed qx,r m 5x:2*tmv+c swjof 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 circular motion as shown in the figure-x)u1 *.k xykmce,z fv. The string to which tfe1k m,v*x .yk)u-zxche 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 from a3j *yj s.8emxv0v a n.tucfo4ou1kh49 horizontal disk’s center. The disk 8xkyj9utcho1 juo*f .40s4 ev a3nm.vstarts 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 mass M =t574f2o cn)g1ikhqd p 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk startgi q2h) ofc1k4tn57dps 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, startb--dsg m9 h5jming at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an9m-db sjh-5 mg 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 3lv.qlr ) h*hpcircle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases unq3 lhph* )lv.riformly 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 oih7p w:ub fh.7yie( dsb*-8tkvs0 x; jf a bucket. The bucket is spun in a vertical circle of radius L by a rope. : 7(s fii.v7skhbpxhy*u;0-ed 8bw jtWhen 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.