95.02: An object shown in the accompanying figure moves in uniform circ7fmbyo3x-cm 8l q9s ;kfp ht*2k7k j-eular motion. Which arrow best depictsqyhf2mkf7;x t*k-p8m -9c 73lbsj koe the net force acting on the object at the instant shown?

  05.31: A child is belted p,s g)b)r/ 0m+trz -kx1sbyh minto a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location sho0ymxzsrhrp/kg +mb)1 b)t , s-wn, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves ikh(8egngs bc/0gkk 2: n a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle m: gkh0/2(egckg ksbn 8oves 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 l17:eqir,lcgak ) dgo1b ld jz3yl.- )speed in a counter- clockwise direction. Consider a time interval during which the particl lyqdi)bog. 7ar)dg:1l-z3l 1ckle j,e 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 clockwise withlw.qn2zk24sb/ej qt d:lkj.7 constant speed around the vertical circle shown. Which arrow best indicates the direction of thdq:7jk/ .. ejl zl4w2nqkt2b se object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smalt-jw ijik(5anz 544kgl 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 girl needs the mass to pass througtj(n5iawgz 4ik54 -kjh 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 horse9klt f 8ikv0qv;vcj-7shoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of thekki7 9v8 lfc0-vvt;q j car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an exvu/ e+u cme(v0periment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagram wicu+vee0 /(um vth $0^{\circ} < \theta < 90^{\circ}$ , 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 osd; 388obfk wvf 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 friction actin8vk; 3d wfs8obg on the object?

  07.19: What net force is necessary to keep a 1.8h.jc hi+*tr y,qzwx6 qvc- ) :dmk4sd 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a spjzwqyrm+x dd)86qc - 4t. ikvh,s c:*heed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass =s t. 2i.b.fjoz 50 g) on the end of an 80-cm string rotating at a const.sbf2jt zo.. iant rate of 4 times a second?

  09.24: A point mass moves along a ho3vc) cniq5pe1 yn5q +wrizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting )ycpq 3c1w5nv i5qen+on the mass as it moves?

  96.24: A 2.0-kg ball is oa, :iizyi)0*d-y, / xfa qp l.0ptlegg g(bc8attached to a 0.80 m string and whirled in a horizontal circle at a coni-z ,e0*i:t y8 cg/gdiy,pal .)xgoafq p0bl( stant speed 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+e34d pj8hn;hbzkmdb yz;2df6ix+ p kfy4 (r- the end of a rope, in a uniform circular motion. Which of the following statements is Nkz h;4d6y+dy b d4emzx( ;p bif8 p+3fr-j2nhkOT true?

  00.19: An astronaut in an or3z h)vzp7nx)r3 g7wxrntk o08 biting 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 dou h0 )worz)tk8r x7 3x3nnvg7zpble the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward unte,9lnc nes9 sp2 mn 1z2*t9yhril the string of length L to which it is attached makes a 90- degree angle with the vertnprn2she ts9n9emy 1c*29l,zical. 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 terrain, see figure /c*yzu7*jfttmh 8u 0gto the right. Assume the car has speed v and the tops and bottoms of the hills have radius of cufu hyt0*j 8tzgc7/*mu rvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a0k q fmxf8ka5/ hill at 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 circle with radius 25 m, as indicated in the figure. Which one of the following choices best represents the a/kf5xqk80 mfmagnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant /,s srzu6ok bh2:-se vspeed. The magnitude of the net fororb:6k 2ev -sss,u zh/ce on the sphere

  11.47: A simple pendulum of length Lhasa point massoigpnea yw3inc)d:4 4- q ,xbfs6(:cd 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 repres(ngf ipb:c is3ew4,yd)a4 cq6 n-o d:xent 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 focvnijzqw ) p))j 3,+k/dp47fxjc3 fetrms a simple pendulum. The mass is released from res qc4xp )p7wnk c+fe))jj, 3vzf3jd/ itt 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 lowest point?

  04.41: A centripetal force of 5.0 ajw)yyk c3)) mnewtons 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,) aycw3jym ))k and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless,xfx7p4z / +sd9 xxvff surface, connected to an ideal horizontalf v zsfd+9p, xf7x/x4x 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 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 verticro 95ey;s0 amjally-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at0o mjy9a er5s; the lowest point of the circle?

  14.23:Two small identical coins (labezfjcw3 a5d.p.led X andY) are at reston a horizontal disk rotating at a constant rate about an axwc zd.3p .ajf5is 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 connected 9n m1lzwje0ixd:+ 7s:rn7 y, yapdi.n to the end of string and moves about the string’s fixed end in a conical motion 70ys: +njdzdpr 1my,a:.wn9 7l xieinwith 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 is in uniform circular motion as shown in the4 u hko1dqta;:b,ia w;c;waa: figure. The string to which the mass is attached has a length of L = 3.00 m and fordac;:t wakh i4a:qb;o,;wau 1ms 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 c/ du68dyn .x+:up kkecm from a horizontal disk’s center.k /pykucddu : 6ne+8x. The disk 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 mass M = 2.0 kg is attached a distance R =1.75 m fp owfrc,,bs7-piqm 5tq s:u:-rom the fixed center of crfoi,5-:pbwqm7u :sps,q -ta 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 aar vtm; fk1i*1oiq;j8t the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throu*1k trfm ;ao8i ;j1ivqgh 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 inidl-96ds tfc 93rrv l2btial speed 17.0 m/s. The object’s speed increases d-rr3t2lfd9cl 9 v6bsuniformly 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 of a bucket. The bucket is spun pb3)nyk555nwf ukp ,ain a vertical circle of radius L by a rope. When the bucket reaches the hi, yk5ku w)ppan3fn5 b5ghest 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.