95.02: An object shown in the accompanyihf :dkym7z)x*yd( o.l5ns s21 fw s)cyng figure moves in uniform circular motion. Which arrow best depicts the net force acting on the obnwh)1y*s cs)y2smdkd: 7y oflz. x(f5ject at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwisc5xn l/o,3axj e at constant speed at an a 5acox,j/3xl nmusement 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 moves in a circular path at constano xod/7w)uti8 t speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circulow7uxd 8tio/ )ar 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 path at constant speed in a k/;g/q a+c4 cc2sfwqd w k/gg6counter- clockwise direction. Consider a time interval during which the pa;cs w//+fc gg46 /qkwgdckaq2rticle 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 clockwbr2kt 5q 4/ey;/x yxv kllr.q*ise with constant speed around the vertical circle shown. Which arrow best indicates the direction of the l5k *rby42;/xxv.t kqeqryl /object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass co:0:5l) h mkp aaambsw(nnected 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 labeled P in the figure, at which lettered point on the path shoul0ahaal5():m :wb ps kmd she let go of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped1qydomq:y8 ;*u d;thf 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 traveling fro;oyu;tm 1y* hfd :q8qdm Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pend o:*74z) 4(cmpo quebrqxo(awulum that is released from the horizontal position at restq4 w(ra4m:o* c be7(ozx) qupo. 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 of a roughoh4 6.noue;ih 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 fricti6uehhn.4 ; ooion 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 af9lc rz;t+s,hizhq4+ circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2hcz9r ;iq ,zfstl+ h4+.0 m/s?

  05.03: What is the centr 7mjs5iis:-y9s n7 4o,7k(nzni naamiipetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotatim 9, ma- ssi7k4yzn:ajinns( 5o77in ing at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radi*x,b u,ktj jc,(;-rrkwk 3dxkus 0.8m with a constant kinetic energy of 128J. What is the magnitude of thej c,*3t x bw,rrkukdx k-;jk,( 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 horizont+d+qq9rj, qpg al circle rd qj+,q+gp9qat a constant speed 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 at the end oxb 5hgzkh7p pphah/8 63w9n;h f a rope, in a uniform circular motion. Which of the following statements is NOT trph pz5a6 hp9/7bhg hwk 8;3hxnue?

  00.19: An astronaut in an orbiting space craft attaches a mass wt n )f+ud/5imm to a string and whirls it around in uniform circular motion. The radius of the circle is r, the f) t w5i/+dnumspeed 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 would be

  07.22: A mass m is pullex:e)d-q4z he +2qdr j)cec-r0.satik d outward until the string of length L to which it is attached makes a 90- degre). h2dqiz -erct-r:kax+s d )4jcee 0qe 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 bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure tocwd,f0tm 9g, h the right. Assume the car has spe9cf ,tdw ghm0,ed 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 movzl xtlch08l+g z:e :v+es 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 be approximated as a circle whx ll+8g0 z:c vel:zt+ith 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 speed. The magn 2hqs6 sw pll0u z:ap:25b kuqeu0,8xoitude of the net force on the sph2oqe8lh kx qu, l0szpw b20u6as u:5p:ere

  11.47: A simple pendulum eees j,+ud:d stax(7 ,of length Lhasa point 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 magnitud,sdxd+ea:7u tj, ee (se 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 strinrw *bv62kx(w 2h n0trug forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following t60rh*( 2 x2ubvwrknwchoices 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 mass swings through its lowest point?

  04.41: A centripetal force of 5.0lxy7ri3,:u6 z3 vypvl 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 made smaller, what happ vzlx:yur i76,vyp3l3ens to the speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surfbglk( mt,3pf(fk) f h9ace, 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 equilibrigm9(bkfl ,(t)fp fh3 kum 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 fm:aabp /-qgi1yp;:s, 7z5xw c.a cebgp;us7constant speed of 3.24 m/s in a vertically-oriented circle of :ami5x a.w/y7z1s;,es b ag -quf7c:p; pcpgb radius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labelatk)cc9 r1k88b wfp)bag afx n::m d57ed X andY) are at reston a horizontal disk rotating at a conf:8:apg 7)ccwba19 atn k xb5 8mkfr)dstant rate about an axis perpendicular to the plane of 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 connected to the end of strrz3o9gwrefce, 6,k r k5+r* jaing 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 and forms an angl k rj5oa3r,rkc6+e,e9grwz f* e of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in1 luodnb-kg3 3 uniform circular motion as shown in the figure. The string to which the mass is attached k1 ludo3 g-3nbhas 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 horizoj0 c vg+,1cwrzgosf3axc-v 05ntal disk’s center. The disk starts to rotate from rest c wcjosgc1 +vz,0x rav53f-g0about 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 = 2.0 kg is attached a 1 zrk5r+utar-v ewu(- qb17 oydistance R =1.75 m from t7ey+o t -5aq1r-wur uk1 zb(rvhe 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, with initial speed).zia ; ud5/)xwlx :xkyk b3f.mg0ewi 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an ang lmx:wzf /3)ekw5ib xidxy 0ka.;)ug.le 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 hbbb6p0wpttw +o(o82 ;cdy ioph ;i*)in 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 ango+ibop() 0ty c;2 b6ipthwwo ;8hp*db le 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 ofl5)m1 ojbqy/l 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 motiom 5 q1/ylbo)ljn, 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.