95.02: An object shown in the accompanying figure moves 3oi6fi)jxnl *wj(gykj6 j u):in uniform circular motion. Which arrow best depicts the net force acting on the object at the instan*jf 6i uw6)k jy:)ojjg3x (lnit shown?

  05.31: A child is belted into a Ferris Wa hg8+ph wqm8(r3z g(lheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force ex z3pg+(8q mrhlag(8wherted on the child by the seat and belt?

  08.14: A particle continuously moves in a circuut,nco-n6zbix*e 77dxls;a oq*d9; - qeq s+tlar 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 ptexs7n;uqq,dn+abd;-siq*9zo7c- x6e l o *t oint 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 aj8t47w ui t2j v/n,foc circular path at constant speed in a coun t8/7ovcn, f2i jwt4ujter- 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 con03f la z*a9bb bj+)23pgkg tkystant speed around the vertical circle shown. Which arrow best indicates the directio)b 2lj0pg*b3b y3zk+ak ga9 tfn of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass con+74 od4kx he hnnw:t,onected 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 n,nhh x k7:o w+ot4ed4above 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 arouykwedy6m3aabk a,73 3nd 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 3aw y7k3y ,a adekb3m6traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple 1emp7pa79 xis pendulum that is released from the horizontal position at rest. At the moment shown771pepa9 xsim 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 rough kzv ; rr2(es utfr c l+,smty6:lhsouu9 27,1iturntable 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 u,i :ts9vou +,e ssht;urf (r2lry m71c62zl kis 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.tt e l)gz)po -5* wm+l,wcjo7p 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless suctwtz*)lm ew7)oojg +5l,-pp rface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceler*3er ud m*p)lmation of an object (mass = 50 g) on the end of an 80-cm st) dl**murpe3m ring rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizo4f s wjk;a4esr(, x5tzntal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the ms4tj;k,4e5 frszw( xa agnitude 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 in2 iqq- qri5ji, a horizontal circle at a constant speed of -qq2,rqij5 ii 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 at the end of a ropeq.5:nfdo9d*v6e s n/feupbv ij :td)/, in a uniform circular motion. Which of thefb65sp) i: edqdeo nj.dnt/f 9:* v/uv following statements is NOT true?

  00.19: An astronaut in an orbiting spapin4)y li(5s7)gs zztce 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, ayz(5ti s)4zp7g n)i lsnd 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 it is xyq9,iked(9 j5l+ozp 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 when the mass swings through the bottoqyi+,po dz9j5l(ek x 9m ofthe arc?

  94.15: A car is traveling on a road in 6 oz;p w3 62nyuvb xx(emaf87ahilly 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. The driver of tp7yae a 6zo w3n2m(6bvfu 8;xxhe car is most likely to feel weightless:

  17.10: A 2000 kg car movekv 0m :j8xi;tws over a hill at a constant speed of 12.0 m/s. At the very top of the hill, the shape of the road can jiwv x8mkt0 ;: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; :qyxrltb:5r ed. The magnitude of the net force on :lb :q rry5;xtthe sphere

  11.47: A simple pendulum of length Lhasa pg kufud d:6v0ci*6rv:inq1y:oint 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 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) v: 1ddi* u6 inqck:0rf6:vguy?

  16.32: A mass connected to a string forms a s4 tct ca4i8j64zz:d4ai4v.h znoqk s9imple 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 gravitational force on the mass (W), and the net force acting on the mass (F) when the masvih t44s49k ct 6z qa4:acj48o zzndi.s swings through its lowest point?

  04.41: A centripetal force of 5.0 newtmyf 0)sj 4)3:to w7ooj/b febuons is applied to a rubber stopper moving at a constant speed in a ho)b3tfysjfw7oe)m o/ : o4 j0ubrizontal 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, is at rest on a frictionless surface, connected uqbe,6d3ls + :ja2puek 3f yt7to an ideal ho fqu+, pase236b yel73 dkjt:urizontal 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 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 spee ;eo,a6qr5mojd of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting a;rmqoj e,o65on the mass when it is at the lowest point of the circle?

  14.23:Two small identicaltg riyu58p24h coins (labeled X andY) are at reston a 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 from the center of dih8 i4ry5u2tgpsk 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 str-u l86 mtry b5a(zh jym*o-,xling’s fixed end in a conical motibhy8 lz-(r5*l- m,xa 6tjuyom on with a constant speed of 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 motiocj8hxx6j y 46;yuy ;mtn as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an j4mhuc yj6xy; ;xy8 t6angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass xozrfr z,sv7 o1f+c61k:(tev11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with:rvrkz+xvff71,(z6ooe c1 ts 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 = 2.0 kg is attached a o avca: e8q*2v+k.ndk distance R =1.75 m from thek+.v2 kdano v:q8*a ec fixed center 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, z(r54odkbky9 with initial speed 17.0 m/s. The object’s speozrkk (94yd 5bed 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 in a circle, starting at the top, with initial .tayct bd6z*4speed 17.0 m/s. The o.za4b6 tydt c*bject’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 time for this motion?

  17.38: A small 2.0 kg block rests at the bottom of a bucket. The5rc azvc1(bm3 * mlthw:wb(.b bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highestb1 (lt. wc*z3vm(cha5:b wrbm 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.