95.02: An object shown in the af qfr8/ 4xjh( ay+-1oh5 kpmqj3gpb5nccompanying figure moves in uniform circular motion. Wrqm+oh 3 8-apf/4( qbkjnf h 51gxp5yjhich arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ft))vhv* 1owy cerris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the totatwo*) )hv yc1vl force exerted on the child by the seat and belt?

  08.14: A particle continuou1ee(k4i)lpa()jlj l u h-(; uafjx4 jlsly moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q. Poilki(lp4)- )1 faujell;h( jau 4jj x(ent 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 nk +( hrytu3l:s 7/vw n2bwr9 o/l6sgxpath at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along thisx/ r2s(gn+/r7sb okwtwn9l l :6vyuh3 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 vertical circle1ts+fx2s; wc5q .vwlh shown. Wh f;qvx1 lw5t+.s sw2chich arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a s5 ita1v4 u9tbo)sn4fv mall mass connected to the end of a string counterclockwise in a ho5u9 f4 )avbtst 1nvio4rizontal 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 go of the string?

  15.23: A car moves with constanh(qt6n2 qmwb tfe -4u1t speed around a horseshoe-shaped path as shown with the arrows in the figurehmf n-t6 eu(21qbtqw4. 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 simp21gz/ 5vs8 e ygrhzo1xmv ),pele pendulum that is released from the horizontal position at rest. At the moment shown in the diagram with ere51 8ys)vm1 ov/x hg2z,gpz $0^{\circ} < \theta < 90^{\circ}$ , 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 )s /c ys pct3os3ocn55rests 2.0m 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 friction is 0.80. What is the p35o yo s/c3t)ss5cn cmagnitude of the force of friction acting on the object?

  07.19: What net force is necessary *ewli*f nq.5r to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictiq*fl 5er.w*i nonless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on mc6 tdq d(mi2,the end of an 80-cm string rotating at a constant ra(c, d62mqdmit te of 4 times a second?

  09.24: A point mass mn15a ;;bnnyqke e9 a3r7dvv0ooves along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the maq 9nb;3noyde1 avr av0nek;75gnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a ho pn-c , 9qdrq7g-;ragirizontal circle at a constant speed of 6.0 m/s. See figure to th-ap9grrq 7i- gqn;c ,de right. The work done on the ball during each revolution is:

  99.22: A child whirls a balo4o rcj tyfo u/1y2g:4,t k6 :zaoese1l at the end of a rope, in a uniform circular motion. Which of the folujyo4 1s2roy k: gztoea4fe:1/ ot 6,clowing statements is NOT true?

  00.19: An astronaut in an orbiti 3yu chbzx92)w yfwy6.ng space craft attaches a mass m to a string and whirlf y9w uhy2ycx)b. zw36s 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 double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward unti0gb j59ht7te cl the string of length L to which it is attached the9 c05g7b jtmakes 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 swings through the bottom ofthe arc?

  94.15: A car is traveling on a re-umx 9zy5l os/g9d*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 R. T 5xs 9ru9 e*mlogz-y/dhe driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant sp vo-,u8,vwdbb u7om0 l1xpy+yeed 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 b+mp by xv-yudu8 v,0 o1,olw7best 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 constant speed. The c(k mry8yk;v0 magnitude of the net for;m( kry8vy ck0ce on the sphere

  11.47: A simple pend;h /rcc/euqc9kwa +5 pulum of length 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 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 rek9u/c hc 5qp+a/;wcon 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 simxc0 fupetp9006 /rwes ple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks p/e r9ps6xc e0ft00uw 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 appliedn: g;g ewo0l;b to a rubber stopper moving at a;ewbl0 n;g: og 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, isba6zv8pv(f lozr*,y ( at rest on a frictionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium *8y6o(,zbrpzf(vv al 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 vertic9n ts*wck;v8xfg x8k+l gs9h+ ally-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at the++98*8f hl9nsk cxkstg xwgv; lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horizontal diskgze1mm; z9so2 rota sz9;mz og1em2ting 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 connected .4:rtqszk o; wto the end of string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a lengthto;q kr4w:s.z 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 motiol)9:-; rwg+yg q+v+pt h losdun as shown in the figure. The string to w:dgwtvsh+ ;rg) +uq-9lp+olyhich 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 fr2q ms lxplh70v,+*7aqezbjszv 2/ 8wmom a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angularlzv vba*2s 0/ xqqz7jem mlspw8,7+h 2 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 mm. tzswfm:qtebfpi-7. b *r 5;ass M = 2.0 kg is attached a distance R =1.75 m from the fixed centbw* b7 t.pm;.mr-ffe 5zstiq:er of a 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 at the top, with initial spcs/r8t x;y,wfeed 17.0 m/s. The object’s speed increases uniformly until it has moved countercloct fc/,;8 yxrwskwise 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 /e as/ sd0seflovnmm 2::amdqtv 5 ,bzgm7)3, top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclocke :vm 7me )aodn/5tm d,2f/mz03 s as:,glvqbswise 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 fa* q oqmdrm,x:,pm7j8 j0w x3is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just fas3pj870 a m :m mxqwrfj,,x*oqdt 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.