95.02: An object shown in the accompanying figure moves in uniform circular dlbxwod lc..+*cxw(-sf93ix motion. Which arrow best depicts the net force acting on the object at the insdc-.l.9os+wc fw x lxix(d3 b*tant shown?

  05.31: A child is belted into a Ferris v72dx q,(0fw lte0wgbs 78jgbkz8z0p 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 tgb70z 0,(0ewfz j stb lk8gvwdx8p2q 7he seat and belt?

  08.14: A particle continuously moves in a circular pet 1bco*nj q70ath at constant speed in a counter- clockwise q o7enc*b1 tj0direction. 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 continuoug: ,fk sqzk yb0-bvd9l o5dt.0sly moves in a circular path at constant speed in a counter- clockwise direction. Conskkfd0bvq5 yob:l g0 -t z.9d,sider 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 speede 40:1i ay riuvn9yn)c around the vertical circle shown. Which arrow best indicates the direction of the object’s r9yue) 0a:nivc 1nyi4instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass co,qe7h -+t8 qo49 o9g0kky ik0cd maypgnnected 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 thek9t ogk m dkpci+, go80y9ayqh-0e47q 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 sp r7 b j)zk34rur(kdjt x0ct,w;eed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes z43x7tjruwck r)bjkd; (0,rt 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 simplw6 :a tk,2envvio0ue; e pendulum that is released from the horizontal position at rest. At the momentee;,iuo:v2t0 vn wka6 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 of a c1v:-we91,j(lva , c1ch 8yibeqkq l trough 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 coefqjt eyw qi- a(vl1c8hv,l:k19c1bc ,eficient 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 kg puck moving in a )le f7o xp;i;dzbt7cj x-f2.mcircle of radius 0.5 m on a horizontal fl cxzi;dp tj; 7o.f2ebm-7f)xrictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acce9x- 88 p(:bfsx,sqescat: j1y cson/rleration of an object (mass = 50 g) on the end of an 80-cm string ro 1/t:o,xsybrc- sf8(nspeq:s98jx c a tating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of 0h eej ,(9xcsnradius 0.8m with a constant kinetic energy of 128J. What is the 0hsxn (9 eje,cmagnitude 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 horiz 3hqeh, 59(stm.gnuojontal circle at a constant speed of 6.0 m/s. See figure to ( 5ogj.shnumt3he 9,qthe right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circtou+i5 j):orm6 9qvlk-/bn amular motion. Which of the following statementsv-r) lj+:u/mb6i5kn 9tq a oom is NOT true?

  00.19: An astronaut in an orbiting spacetn.hcifo)(i22r4 o 7fntui7 m 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 mass, radius, and speed were all to double4 in u (moit fnrtfc2h7.7o)2i the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward unwzl *q: v9krq6til the string of length L to which it is attached 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 wh9 kwqqvzr: 6*len the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on ae*r1amdt2tq; , sm u,h road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radttr2*s ; ,uhame,dmq1 ius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves jtptq+a-p x(8over a hill at a constant speed of 12.0 m/s. At the very (qppja+x tt-8 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 exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant spe hm0 p5+qq*eqt e/,dpdrg-b:d1 r7cgled. The magnitude of the net force on the sphergp pqetdre: 0+ql g-,dbmr1c*q d75/ he

  11.47: A simple pendulum of length Lhasa point mass M released from resrw1 zmn6,grr 2rj9 cjrt1f ,7kt from the horizontal position shown. In the absence of air resistance and friction, the mass swings through the arc of a circle. Let T1 2rw,tmk1r6j, rcgn97zjfrr 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 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 e6e (t-/+dvo s .bfs*nk dv/csh t(fk)simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the tension in the string (T), the gravitat d*eds+f(f )nk svc/bst-(kv6he t o./ional 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 forcr q5 5-huu)t-7j prt08tymsjpe of 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is ma5jpt- 5yh0muspj) rr-q8ut 7 tde smaller, what happens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictg:5i3j2wol t iionless 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 o t5iw2:lijg3is 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 constat3ty,g3ad yc((q3 )fc6aq ae*ghpy2q nt speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on*t(cp) gyqa6( qgy 3,3qh2eytc3fada the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston 6i afqg8m f+)ha 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 fm) 68ghfia+q 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 tbsb3h5k/ 4itu he 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 stri k4t3uh/ sb5ibng 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 uni/uv,ficwe;7x form circular motion as shown in the figure. The string to which the mass is attached vxe;wu,7/cif 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 rek*dt(7v 3cvhi m4 aa nr1wz5)w99za bsst 30.0 cm from a horizontal disk’s c vz) a9d(hivm* cawk9bz13nwa5 trs47enter. The disk starts to rotate from 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 wx cb6;j;ey)t*sgp b of(s;a2sith mass 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 rot(a62*ssf)s y ;cg;ojbp ; exbtating 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 speed 1baqfe h7q4x- b e8nt oxykkx1/;49(i y7.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle of(e kn ey/fxb9hit;y x48q7-k xo aq14b$55^{\circ}$. 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, w;eau9 , ivys9 8abws,e 70vvssith initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throughv v78evbus w9, y9as0s,i;sa e 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 bue1a .3*b3 xloni a7vy .-e-wkkkja*/ohewu(a cket is spun in awia o*le.bky1j hewun.a*k- e( kao 3-a3/x 7v 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 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.