95.02: An object shown in the accompanying figure moves in uniforxpwz 97ux 0-gfu8 *zwfm9ms ej /q8,mum circular motion. Which arrow best depictuguzw97ff9je 8 sm xp0q/wm8u*- m,xzs the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris j7j xhm6 ny) tyh+kupb.l0*r.Wheel seat that rotates counterclockwise at constant speed a6b0tn.y.pkh*j7 +ymj u xlh)r t an amusement 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 7nzmw5,o sm (qv+g ag2moves 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. Point Q is exactly half-way around t2qa,m( 7ns w+5vmzggo he circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves in a ci, fs bv*+ggrgf0o 43ju 61ykbxrcular path at constant speed in a countvy 1jox0*ks+,f frg b 43g6bguer- 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant spe9u,ta eot o90 c*;phrqed around the vertical circle shown. Which arrow best indicates the direction of the o09pa*cuhrq9; tt oo,e bject’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a n0a 4kt yd) /mg1tsyw1small 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 frok/ d1nm0 )swy 1yg4ttam 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 constant spe fd. (;kyuvg05mio+o/vfpy v,1f(r lmed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the dirrml1 fv0.y+ imk(u,pv/5d ;fyvogo f(ection of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple penpvv (e:sic3ig,9 j0i odulum that is released from the horizontal position at rest. At the moment shown in the diagra v0j (e,isvo9cpgi3 :im 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 2.0wd3 t9zd cx8oib49m.m,rg 5n im 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.n gm d4i8xzm5. ,cw9itr3d9ob 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 mocy fn3;vw,yn9ving in a circle of radius 0.5 m on a horizontal frictionless sy9y n3nvcfw,;urface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleratipp .yl;74swux vegmchgr f/1 19ne 7i6on of an object (mass = 50 g) on the end of an 9gs.11 eepi gnyv;4hfr7x pw6lm/7 cu80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m withr*m4 ibg/q m-1criu:k a constant kinetic energy of 128J. What is the mag mg/ :*4u-irk1cqim rbnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached 1;b; tnpxrh 03suuku -to 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 wxbhurnptu -k ;s10u 3;ork done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in hb 67dq2 t /xvzdl*x+l5j * somzjf9)ma uniform circular motion. Which of t+fqbj lx/ mx*j2l v)z75d6smto* dh9zhe following statements is NOT true?

  00.19: An astronaut in an orbiting space craft6ra +ha6leee 4 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 double the tension required to maintain uniform circular motion 4ee6 hr6l+aeawould be

  07.22: A mass m is pulled outward until the string of length L to which it is ai0lo 2o(e9whk ttached 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 swings thrh2 kiel(o9 ow0ough the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly tyf*54vd0r hf1v b m 4j66xnkfeerrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the f0b6 jr4 e fkh*fy16v4vxmn5dhills 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 conyrt:g)tbxgtt/o6c ;i0mfg7 1 stant speed of 12.0 m/s. At the very top of the hill, the shbitt ;gtgymco/fr0 )t7g6x :1ape 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 exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constan k0bd+17uho9 uf;+0fugcfo wu t speed. The magnitud;fo9wdfo u1c7gu uk 0+u+b0hfe of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M r2-q 1 1 *r+escsbux 7.wkkcyofeleased 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 th 1o-c+71 s sqrw efb.y*cuk2xke 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 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. The mass is reljwt4u* sbl 10deased from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of 1s* d wjulb04tthe 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 /: unod9ok::iv yc u)sa rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radiucuyok::od/ n )s i:v9us 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 surfacx;jx(f 2q6ur re/ )tworqa 2z1e, 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, what is the necessa o j2tqrz/)xrfrx1q; eu26aw(ry force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mas2ee u;, je )nus,jw*cvs 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 mas;*c e vuenew2)u ,,jjss when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at restoqk6txk7py7.hs g9 h: bn a horizontal disk rotating at a constant rate about an axis perpendicular to the plane ofp:q77 kb .hky9g ht6sx 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 co +3bggoi xu6oe t,)b7upo(rz :nnected to the end of string and moves about the string’s fixed end in a conical motion with a constant speed o7o xtue:u+ ggb36zpb o i,()rof 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 the figure. Tg:vaibr+4 nx0y 95xgohe strinbrai 4g x:90n+5v xyogg to which 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 disk’s 6z1voi4gi y -3k.oct ,ju d,gacenter. The disk starts to rotate from rest about its center with a constant angular acceleratiz k,ui3 -i oc1dg 4,vtog6ay.jon 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 =1.7+mte+qsbn . -m5 m from the fixed center of a disk as shown in the figure. The disk starts rotating from reetn+qs m m.+b-st 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 speed 19w+qdm9urh( 4 ehbdrj9i :ip07.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throu hmrq:jw4hp+ rb9 d9udie (9i0gh 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 initiw*jjq , lrb gsyr9- o+qvb8t-2al speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throug8jovq* j wys qrg-+l9trb,-b 2h 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. tf (h+l1xye;uthje*5q+zvu6 ) e u t6cThe 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 thu 6+equx ; uhte1fcv6(h )tyz5j*lt+ee 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.