95.02: An object shown in the accompanying figure moves in uniform circular motw pl61p6o4z. x *,hd dtwazj4;b eo..bhf +gjoion. Which arrow best depicts the net fo. ;z.1oo6 j4egzl dphtoh*xp,fjaw4b .wb+ d6rce acting on the object at the instant shown?

  05.31: A child is belted 4o;c iv fz-ql+)nyj5k into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the loc-f;qol+jvc5zniy )k 4ation shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at consns v. :4zmw88 (g2yz *tkr9hann no1vhtant speed in a counter- clockwise direction. Consider a time interval during whioz*ng.h1 thwv8k rn m4vsy(2a:nnz89ch 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 p w jopo0;meo+2vha c-4me* 6flath at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves alovm m+oc4e ojewpfh6*02;-oal ng 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 amf(1:dpj 0wm p;00bcd2kzbjs round the vertical circle shown. Which arrow best indicates the direction of the objecb w fcd1;p0j zd0b:0(mjsm2pkt’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirlso+8-cw5q b,nmn r vjl.tt ou3- a small 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 from above the twirling mass. If the girl needs the mass to pass through the point lab5 m-3t+8 rn t vqobwnc.ouj-,leled P in the figure, at which lettered point on the path should she let go of the string?

  15.23: A car moves witf93npg3c fo: xc .n*shv+ zmh0h constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in trave o:+hsxg0vh c3f93pznmn* f.c ling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simvm7c:w lep ecp)d+:mtxpo t c(s3 ;6.cple pendulum that is released from the horizontal position eett c3()6l.vpo;cmp:pc +xm: c7wsdat 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 rest* n.cvgk*ikyloid+7m310y 6gly . kyjs 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 friokn06y1 v y*kmild gi.7k y.lycjg3*+ction 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 c 2 qjtp*g .,rgpu4kls;ircle of radius 0.5 m on a horizontal frictionless surface with a speed o ;l p.,st*jgp2kr ugq4f 2.0 m/s?

  05.03: What is the centripetal accelf:e1ygd)f 3f rh r3ac6eration of an object (mass = 50 g) on the end of an 80-cm string rotatinge fghff:3d1 ray)cr36 at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.q(su9f f;d466/ixi o.d srquu8m with a const6qidi x(q;uf/u4rd s9sf6ou .ant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attached to abvs28y xr/ e2r,6hv fb 0.80 m string and whirled in a horizontal circle at a constant speedr8r62ef2 v ,bvhsy/ bx 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 bal1exs67c 1m9lb w iw4mol at the end of a rope, in a uniform circular motion. Which of the following statemxl wmwi6 9ms17obec1 4ents is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to q)5unvm/pr3m 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 ismr q5mu3p v/)n 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 wh( st rekq(ie1 p6mr(t(ich it is attached makes a 90- degree angle with the vertical. The mass is released from rest and swings through(r(((q k6iet1 prmts e 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 h)be8 hi.f:. gnh-grfjilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of thnjrifg.8-hb eg : h)f.e 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 cons./o9n jwrp1xuo0wut vv8.w:c tant 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 un ovjvt1xpr8.9u0 wwcw ou/:.pward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant sbx98+uh9ivykx uvx 1 i8o8a 9gag/:q epeed. The magn18x9 a:9xgko+ 9qxuvug/ behi8 8viyaitude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa poins nevc/ lq 5-i9*ii7ait 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 on tlv*7/iq5 iinec9sai-he 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 ,ox:o6g6t qm yk1gvqx)i(h : hmass 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 gravitational force on the mass (W), and the net forcm6:( 6,q:gxhyvioxg h)t 1 koqe 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 sto i/kamk qfh0s0) :q,tspper moving at a constant speed in a horizontal circle. If thek/m,q )sk0 th fsaq0:i 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, is at rest on a frictionless surbfyac , hp2nf+sku 4-2face, 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 snf4u+2-b2ky fpc ,ahcm 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 ab:6chmf*vyitt he+ 7 6 vertically-oriented circle of radius 0.75 m. What is the net6et bmif+7h:6*y v cth force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at resttfgcj8ju 04w47vi-u x4v. tbhon a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the vhjx 48u c-. wftjg74ibu40tvdisk 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 to the end of string and moves about the swp7.ffvpsyu 8+a; 1,zvatyrs144qt string’s fixed end in a conical motion with a constant speed ofy . favp;+tyt7f 1r1sa44vs zw q,ups8 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 figu :l 7xgo4ks +wag99bkure. The string to which t9a 9 kgu4 k:7bws+oxlghe 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/itfh7((7 cg cs-h*q xxb pa0y at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a c( 0g 7q(/h-x7fst*xpachyb c ionstant 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 cw 21 g2fge-5iky5ld eojv2v:=1.75 m from the fixed center of a disk as shown in the figure. The disk stark 2-cgl52 12jd wvf5ei:eyvgots 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 specx s8i 7wsf9nob 71m9eed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle9bxw7987ios m 1fc sen 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 i jzb/w+z;sf 6dn a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniforms /jwzb d+zf6;ly 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 time for this motion?

  17.38: A small 2.0 kg block restsr-h61a/ pc x5zx.dc61:d/os adi onwj 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 motion, it moves just fast enough for the block to remain in place 15 / cs-z 6adoondw/jcxidxr 1.hpa:6in 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.