95.02: An object shown in the accompanying figure mo/gg9kmz wyr(0t f0rijs lnu*x 9z.3r.ves in uniform circular motion. Which arrow best depicts the net force acting on the object at thzu0 ktzyl*/jn. 0.9xwrg3gi(9 r fsrme instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotrif dtawht( +i k.) km0i-b) s1i8r4uhates counterclockwise at constant speed at an a)i8w i1t+mtr 0(b ihas-4r).i dkfuhkmusement park. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant speed in a-p8u2 r/ vge6p 8adbps counter- clockwise direction. Consider a time in r8p/gv6p2db- 8 uapesterval 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 circu fi0h d y2s3ww1a5ew:9t6 q1u.rsiljtlar path at constant speed in a counter- clockwise direction. Consider a time interval during53ws:stl d yh erauqw9j2i016wft1.i 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 clockwise with constant speed around the vrlqx j1rqm, 3 (gv,9 /ulzwiv3ertical circle shown. Which arrow best indicates the direction of the object’s invqv13j( l3zw ,iu9qx/r lmg,rstantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smync sfx qi0h,;,ve-; pirx e63all 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 through the point labeled P in the figure, at which lettered point on the path should she let g6 e; hrive,, fiqpsn y3;cxx0-o of the string?

  15.23: A car moves with constant spee 9enhnlh *+9bf( 2znvn3kkq 3ym*8 mhud around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choi m(unmnyk+vh3hzq8e2 h*l kf9bn3*n 9ces 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 simplegj ek)f;xsl * i yw(oc2g7:b;u pendulum that is released from the horizontal position at rest. At the mome)xl;y:;ugi7sfg o k 2j(ce b*wnt 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 frodu3ficc7 /7d wm 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.du7/d 7c wc3fi50, 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 nece yrww;q. .tcm;.k lw2xssary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed 2tk.wwlywcr.;qmx; . of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (b9 fmqlac, k5an2ph a6 (o8gtvks;48i mass = 50 g) on the end of an 80-cm string ro8m256tqaf in;gpcs h 9a k vko4bl,a(8tating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizont2dy7pjb m4o);.4ggsdy )lh 1ui3ng ck al circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it hglbgp m 7ddn)gi44)k 21jou ycs 3.y;moves?

  96.24: A 2.0-kg ball is attached +wb8i.ou uug1to 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 b8oi1uu+g wu .done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a unifor8a :yhh4mr ;ydxdf 0.im circular motion. Which of the following statements is NOTh:8f m;.ad4yd0i xhr y true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a stri h dczld en5cx3-+sw-3pt:/m dng and whirls it around in uniform circular motion. The radius of the circle is r, the speed of the mass is v, and 3d3 ce /nl5-ddh :spcxzmtw- +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 string of length L to weayi8 (:gho0 yhich 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 tension in the string when the mass swin:8ayi hg yeo(0gs through the bottom ofthe arc?

  94.15: A car is traveliz 19ufkf:m fs94fu7 nthp4is- ng on a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature 1u4m4zu kf9ntffi p79f sh:-s R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of ;jrrj1o n:c 9s80.m xioki5 hx12.0 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 figuresroim j;c8k oi51xjr. xh:n0 9. 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 1ka0 )*rs hn3 )3t3l x:l0q jfn ut,kii*mapmymoving in a vertical circle at constant speed. The magnitude of the net forc1 3t0i*m0m3sn,rkujyl:aq ph n3 x *tik)alf)e on the sphere

  11.47: A simple pendulum of length Lhasa point 4xy) 8wcgm 2fw9; qlzemass 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 represent the magnitude of the gravitational force acting on the mass by the earth, and F l9 fw gxm8;z2cy4q)ew 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. Thejvq8)5howjkv-i d +* (trgcl ; mass is released from rest and undergoes simple harmonic motion. Which one of the following ch 5wgd8 v*+l;ot j)ivqr- cjk(hoices 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 newtons is a*q pn)x6d+jwio ,b m uk6w2el5pplied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is x 6dq)+ikej 2, ubnl*5 pww6omapplied, 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,2z8uc ( ybar3d connected to an ideal horizontal spring that is upstretched. A person extends thydcubr3a2 (z8e 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 masj o6m+ u.ho/cj+w y-hxs with a constant 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 lowest point of thew.h jho+yuom x6cj-/+ circle?

  14.23:Two small identical coins (labeled X andY) are at re9zfffi jqd. 2,ston a horizontal disk 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 j9fi ,qf2f.zd $d_x=\frac{1}{2}d_x$. 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 moves abo2a3cnah 5 .nnkut the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a length of 2.50nca. h5n kna32 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 uniforr9yj.u r y7wq7m circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.qy 9 77jrwr.uy00 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 a horizontal disk’s dl 2qx7oasp;)9l*;vq) ;hxwm rnadw, center. The disk startw vxnql x*7p))lao,;a md2r;h d ;w9sqs 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 is9m+ajo0 eokn9 4ma ux8 attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk stara o o99eun0mj x4+k8mats 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, startingvu;wq 29q a7sb hcgz,2 at the top, with initial speed 17.0 m/s. The object’s speed increases uniformlvwacq2z2 uhqg7 bs,9 ;y 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 moveszfja 6;5r7bgif7k d0s in a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise thrdik5a 7z;rs0gj6 ffb7ough 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 r ,mze jo/j(.orp a h0yu/l6lp-)i0mkw ests at the bottom of a bucket. The bucket is spun in ae/0myaih jl.mwo)/- jl(0,kzp 6orpu vertical circle of radius L by a rope. When 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.