95.02: An object shown in the accompanying figure moves in unie/7dcb nc)uk 2form circular motion. Which arrow best depicts the net force acting on the object at thdc7k 2 )eb/cnue instant shown?

  05.31: A child is belted into a Ferris Wheel seat that r0mdm6e*hu t :w:0 .za 4cg2k xer3mcwbotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best rewr0tmd:6zexac:h*2kmu 4 .0eb3 wg cmpresents 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 in6ha bbyc8h 00rwzgyd1y e*4 4a a counter- clockwise direction. Consider a time interval during which the particle moves along this *gh804d r04 z eb6ychybwa1ay 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 speed inx ;b .k *pdi69sey/tbvuqh4q) a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q.qie*hpyt/q4;ks b)vdx9 6 ub. 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 thezegvjqjxvz *7 * 20ku )l+ndy5 vertical circle shown. Which arrow best indicates the direction of the objectv05q2 lx 7dez z **vjn)yg+ukj’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small -unp--(i :sdr ky kiye5*ccr 0mass 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 needr--krec-:uisi 5k py yn* d(c0s 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 xz. l 6k1w9alfconstant speed around a horseshoe-shaped path as shown with the arrows in the figurl9xfazw1. 6kle. 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 perleygrt-a1 v1 w:07d raform an experiment with a simple pendulum that is released from the horiy7larg1a:1-0 vtr w dezontal 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 o(d 4 v05 k;del5+ ozccgkwn7z2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 seconds. The coefficiedkg5voz0 ;wnk5cd+e(o7z lc4 nt 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 kgcgbq47wpkj /9-jx- u d puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a 9juk-dx4-pc/g j7q b wspeed of 2.0 m/s?

  05.03: What is the centripe*h) ufkadbfo muzcj )m7*-j .8tal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times )d *u) 7fom.jj- 8bcmah*ukzfa second?

  09.24: A point mass moves along a horizontal circula pik8zx :s70 xu fnu7o)4b8uhyr 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 i7xpk78iuh0 x84 yu:oubfz)n st moves?

  96.24: A 2.0-kg ball is attogcdks7t22 ( vached to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 c2k7g(tos2 d vm/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls +p/a 1yy.-ut2jh1dd 8smzmwpa ball at the end of a rope, in a uniform circular motion. Which of the following statements usm a.2m1t+ph/y8d dy-wjz1p is NOT true?

  00.19: An astronaut in ans s)u h;:*gbhz orbiting 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 massub* g ;zh:)shs, 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 lbzno)aw2g6t (je5rl;n i9x-which it is attached makes a 90- degree angle with the vertical. The mass is released from rest andlx wabeg 2r-o;9nzn()i tl6j5 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 travelio5hz ;peqj4 .rng on a road in hilly terrain, see figure to the right. Assume the car has speed v and ; ej5.qph4o rzthe tops and bottoms of the hills have 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 at a constant irx1x32znwz y0 wsk u q3/mj3: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 radwr uj/s03 xn3 31ziq2wkzymx:ius 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 conse6 2o2bw*a0xq vqgiq7tant speed. The magnitude of the net forcewabo 7giv 6qq0q2*2 ex on the sphere

  11.47: A simple pendulum of length Lhas(xl ynslayl,lvwk:6n nq0b:/b(m+s . 2bj +rwa 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 (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 descrix (vb(s:y,nw+nkj0bw l l:yl2 /r as l.m6qbn+bes 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 ma u rc*f8s6ytspr) m*y*gt-gu 0ss is released from rest and undergoes simple harmonic motion. Which one of the followifr gg0yt)scyus *8 tupmr*6*- ng 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 nq62bf;f9cztbs s (,q o*le9ch ewtons is applied to a rubber stopper moving l ; obftc6h,f c992 sbesq*(qzat 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 stopper?

  05.28: A mass, M, is at rest on a friction (jsq(ke;a-i ozcnm,(i(l:ohless 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 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, whem(, ko-cj( (sq;za:l i(no ihat 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 col,hqj3ph v-,ort) cy fi:hp 13nstant 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 the circ )h, lo1t3-iy: vh3hrcppj,qfle?

  14.23:Two small identical coins (lrxv-*tj3t ; y.w-cmk cabeled X andY) are at reston a horizontal disk rotating at a t -wcxjkymtr.v- *3;c 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 connected to the end of string and moves abouq4iv2+ wr);- i 1 euuebg7ebsut the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a lengthbv)rw ueq1 47;sgeiu u+ be-i2 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 sc64,v outmd1 ahown in the figure. The string to which the mass is attached has a length of L = 3vu tc6om4a, d1.00 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 a hor7xx /dl62 lb kz ;ltzq)o:o.lbizontal disk’s center. The disk starts to rotate f qod2 ozkz6lll xl7tb ;b:x)./rom 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 msd - 5hcfuhn+.w1vd3p qsab:q 4b fl;1ass M = 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 starts rotating fdh -wupv :41.5dqs 3bac+b ffsn;lq1h rom 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 spenm6wdbo 4a0nx.zz ;77 pbuk a)8fk.ghed 17.0 m/s. The object’s speed increases uniformly until it hasa6b )7kx.nan4 7 fo0h8;b kzz .gwudmp 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 a ccr; 5h/ lhh;c7yru r-o;t fs*xircle, starting at the top, with initial speed 17.0 m/s. The object’s speed ih*r5;t/h yxro r7clf;c uh ;-sncreases uniformly 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 ;2c elbrcm:k/b b,u8mat the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When thb rc2lm/: , b8eb;mkuce 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.