95.02: An object shown in the accompanying figure moves in uniform circular mrqn/h8f8evl0q ;j1 0j no0nlo otion. Which arrow best depicts the net force acting on the object at the insta0noj1 lv8l 8hnq fn0oj;eq0 /rnt shown?

  05.31: A child is beltefg jcefg(043gd into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the s (0gej3g4c fgfeat and belt?

  08.14: A particle continuouslbn k)ey ,c:i6z0, qbg;scch4iy moves in a circular path at constant speed in a counter)cqk:e zb6iyis;b4 ,0cghn c, - 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 speed brz/ n-fx2mp6in a counter- clockwise direction. Consider a time interval during which the particle moves 6-fp rn2bz /xmalong 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 co06 xxlb:xm o*c;ehb c8nstant speed around the vertical circle shown. Which arrow best indicates the direction of the object’s instantc;bxc:0 hx *6elo8mbx aneous
acceleration at the point labeled X?

  12.11: A girl twirls a small tdi9k*r70i msmass 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 lette*ki0ir m9 st7dred point on the path should she let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped pa8wxct ,z4h l) ;ad)uyqth as shown w)cxy,)zqt l d;h8 u4awith the arrows in the figure. 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 simple pendulum thatidmwc v +l3. zrjz-6.uv/ xnygh)yhaor z200/ is released fdzzmgzhr/j l+y.0c vh )xuwa3n2o- y./ir06 vrom the horizontal 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 2.0mahmj* w.jkn(jk;4*e m from 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 0.50, while the coefficient of static frictkjn(ham4jj*e.* k ;mw ion 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 :-s04x-z )ofnrbue iui e:, bfmoving in a circle of radius 0.5 m on a horizontal frictionless surface with a speeors,bx n:-:zfbe-0)fi4ue iud of 2.0 m/s?

  05.03: What is the cent30rn io9 e:uxnona7 u:ripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotatoe:x on07nua i3u :n9ring at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius64rvlq3mm5p q evf7g2 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the ma26em qrq3m gf4pv7vl5ss as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string auntpy 0yo f9fa ( di68b u+5eo/pqk6*gnd whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to p/uq bu5*fa(d +gpe6n ifty89 y0oo 6kthe right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a roqn )bo1 f2y0 f-k5jpkepe, in a uniform circular motion. Which of the following statements is NOT t0fbje1f ko ypq-) k2n5rue?

  00.19: An astronaut in an orbiting space craft a 4 . /avvc;ypejqxcv9l:uu, (kttaches a mass m to a string and whirls it around in uniform circular motion. The radius of the (vuvvl 9cxqa.;p:,u4cyj/ke 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 double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the string of lengthad3zp lbn9)8s 9j g e92uhpf)l L to which it is attached makes a 90- degree angle with the vertical. j)ldhsua 29ezgbf83p9n)p 9l 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 trav 2p5gs+nhkqi:7lwux /eling on a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and botxk/ qg2np5+lws i7hu:toms 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 speed of 12.0 0cv ee+hp1bxm:k8f ,rm/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 magnitude of the upward force exhkfxr,:0pe18b+ve c m erted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at co5 of:4ygq 6dc uci+k,qnstant speed. The magnitude of the net force on the sphereq5udyikcc4g,6 :q f o+

  11.47: A simple pendulum of length Lhasa point mass M released from rest from asntgzy4,y./ 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 thyzyt,a g.n4 /se 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/,q bw+n0 uehxs a simple pendulum. The mass is released from rest and undergoes sim/q 0+nwbeuhx ,ple 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 newtons is applied to a rubber stounnd)6li : ck2k in;8upper 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 spee u8niic)uklkn 6;:dn2 d v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an ideal : tzh2h 7+tt7c nmioj wc*y/qr ;4joj2horizontal spring that is u2;oy jhhw ti24t7qtj r+7c/c:jzon m*pstretched. 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 b o c2p;3w.toespeed 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 theweo2; o3.cbtp lowest point of the circle?

  14.23:Two small identical coins (labeled X anrngsq+ 7zr 6jq1t 7vb2dY) are at reston 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 r2q1t7z+6j7rg vs bqnfrom 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 about the striv5td m0w9 xcx4m+z l75qfq)aang’s)v tdmxa xf+ zamq9c l57054wq fixed end in a conical motion with 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 unifo f+/x:do zwm pme/0y5k w3eyb-rm circular motion as shown in the figure. The string to which wk-/e z+ m5wxyye m3df:pob0 /the 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 a horizontal d,k/vwjjt/d: i*h ( vcw5t+tua isk’s center. The disk starts to rotate from rest about wa t/vucj,(* tid/5 +jtkwhv :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 fg4g.. +)1kxclkyle: vy emmtoh-a+0prom the fixed center of a disk as shown in the figure.l .0lc+ m+ .4mek-:g tpxyyh1 )kvgoae 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 at the top, with initial spes x (mzf7 ayq5jc+7xt)ed 17.0 m/s. The object’s spescxya 77tx j)qf(+zm 5ed increases 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 final speed of the object?

  16.40: An object moves in a circle, starting at the top, with initial spj n aw7 p37 ikb:7n(f0lm4eilgeed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angbgj4 iilnpw(lka7fe0 : m377nle 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 bottomb1 sn*j7p x3wbc z/*rt of a bucket. 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 fast enough for the block to remain in place in the bucket. When the bucket is atjpz/b* 3x*c tsw1n 7rb 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.