95.02: An object shown in the accompanying fbleh .)(ye2 irw f;7okigure moves in uniform circular motion. Whichekyi r) hwo7l fe(.b2; arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwisecl.l- +d;5is tsk87jsqm- xwx at constant speed at an amusement park. At the location shown, which direction best repre-i5sdl7s;sm -lxcw.kj 8t+xqsents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular paf ws d 3g7,w(px;2sblw 50j c-8wa4ldfa;natmth 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. pdf7 ;w wtagmbw 8w3sl-4nx5;0a(f,csja ld2 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 cis8m5 pu.sp.ti rcular path at constant speed in a counter- clockwise dirms5u.pps8i. tection. 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 speed around the vertical circl5:pt 0xwrtc brvcow* 7u;o .0ke shown. Which arrow best indicates the direction of the object’s inkt*07xoo b pctw:wur.5c;v r0stantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass co1pl d8faggb cq73s .xw*j4yp9nnected to the end of a string counterclockwise in a horizontal circle above her head. The figure showw9y *px3.gqs p4d a fb8ljc71gs 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 constant speed aroundb.p1 huvwn 6 /ui0p7mi3n ka.k a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choicenn3. kuvkap76.p h/0ibiuw1m s best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Mob j( 3h 5xry42:sda5s ookh)yton perform an experiment with a simple pendulum that is released from the horizo ojaysx5ksrb2h (dtho 4y35:)ntal 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 2.0m from the center:zdl; 7 ,w imonkv4p 1(*batj4nqn9n e 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 magnitude of the force of friction acting on 1oid7mkn 4a (n b;n ,9tn:jw4qve*zlp the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck v1t hb4 /f2+ wyalj2numoving in a circle of radius 0.5 m on a horizontal frictionless surface with a sp21 lav yt/4ubfj +wnh2eed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object v)twffnl;rt k w;tl.mqw8g s-r0-(s4(mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a svnwrs qtfk)0(;;t-fwg 4l8.tsrlw- m econd?

  09.24: A point mass moves along a horizontal c1+q,u1djtpi 4 ox7omm7sz,e093 lsk )svy f cxircular path of radius 0.8m with a constant kinetic energy of 128J. What is uzds3xk+ovs4i1os c1) m9q e,xtjly7,0pfm7 the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball jo;dvvh0;r4 5 2vzr(.y 7zoagq c)xugis attached to a 0.80 m string and whirled in a horizontal circle at a constant spee)rzga4o 02v;;z5 rh.jgv dq(cvx oy7 ud of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball atu fmfki+,c8 o1 the end of a rope, in a uniform circular motion. Whici kc1f+,of8 muh of the following statements is NOT true?

  00.19: An astronaut in an orbimp/d0eq+ xa ,zting 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 m+dzq p,/ x0aeof 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 length L to which. p3dr0he7b99f qvdk vvqalr; h0:lu6 it is attached makes a 90- degree angle with the vertical. Tqa:dv0 6 rreblk9;v9.lhfqv703 pduhhe 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 road in hilly terrain, see figure to tviq(9mk( edd9 ;g p*3ft. ovjjhe right. Asstp9qikmve v9*(;f. djj do(g 3ume the car has speed v and the 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 overkdi,i9e t,b r h,e+vp5 a hill at a constant 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 radius 25 m, as indicated in the figure. Which one of the following choices best represents the magnitude of the upward foke ,,5vi9+,b redhpt irce exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant -db0. 3uzfryao tu 12d*-n* amwzt5nlspeed. The magnitude of the net forceda f.au1tz -t*nb5 ylonm 2z3*r0-uwd on the sphere

  11.47: A simple pendulum of length Lhasa point mass M rxebo/-n ha(1t eleased 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 representt(b /axh1 neo- 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 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 releasefqx-j nj ei;8m 5njd:3)ktrpe3mp -*yd from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the tension in the string (y85n-ek:- pm 3iqjmd 3 )pjrfe*jx;n tT), 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 saki;l .efv8:-lu +md ktopper 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 speed v, and the frequency f,i ;lla-vdkf+ku . m:e8 of the stopper?

  05.28: A mass, M, issiyw0 6ii(gj;83 heb*pl q*n jy;hi g* at rest on a frictionless 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 hjwby gj iph8*y*e si(ilg*60q ;;n3iby 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 ve e4b7lea+hh w*d0bo61n,b bimrtically-oriented circle of radius 0.75 m. What is the net force acting on nhi+06 b,lw *mbea4b 7hdeo1 bthe mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston a horiznxxsg+;lkyj yv-1 (d)b2dl(d ontal 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 frol1x (dyxv k2dynb) s+;(l-dgjm 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 connectegr90g 43,1 ue-sy t8x ngpew8-jmoetzd to 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 length of 2.50 m an-sezwtn x0-34m ,uo8t1 p8ergjegg 9 yd 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 zft1 vi c 677heqyznu-j9g4z6circular motion as shown in the figure. The string t 6h7-eqtu nzg4vifj7z91c6 y zo 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’q0 lsfj;;1fs l6fbr/i5o x e(ts center. The disk starts to rotate blrotq(f5i /0 fs;1e6;sjxf lfrom 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(m hiw mod).ug)cq y*t5 lzt9n.b5w9w.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 from rest with m)w m.z 5(qy9lc9.w i5hu)tw*dbntg o 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 .ktt1cp lvq+ *phlo-ws ,7ea;initial speed 17.0 m/s. The obj*l, vq7wstke.a t;lp +o -1chpect’s speed 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 ii- *k b- 2c+efc.evhrs;m/s ly+j39ucztvj v5n a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an a t/rzk5v+ihuv*e92-; cvcby+ s jm .c3fsjl-engle 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 bj:qcj7cp n8, :ssc imnwh2l 19lock rests at the bottom 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 motionisn 2 1csjjh8 :wccl 9qm,7pn:, 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.