95.02: An object shown in the accompanying figure moves in un7imz d,t 9chy:q cm n02gc,- lq9)efldiform circular motion. Which cd7gzlfil nt: e yccq29mqm)h9- ,0d, arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is beltee6:h:xk5pvmun8hm0 +) lf zr;r3u s pgd into a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direct ::r n hsg v);pkfu06uxhem zm5r8p3+lion 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 constant savw37 h ;0s*fbj+tacspeed in a counter- clockw t;0c s +7s3hfv*awjabise 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 velocity during this time interval?

  08.15: A particle continuously moves in a circular path at cogiah +zqh)bm1kq30 x +nstant 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. Point Q ish)3xz0ga+q bh imq+ 1k 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 ctk m-2 -elq62r)xcpzs/c lfe(ircle shown. Which arrow best indicates the di -lc2 tzk/e)-6qscx(2 erfpmlrection of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to 3fz+oxw8y.cf 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, atfywcox+.f 8 3z which lettered point on the path should she let go of the string?

  15.23: A car moves with cox8f )zx6hls l po9f1x,lm0pbz s9 h8l9nstant 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 tsp 99hzx)1xbl8ll60 89z,xsoh f fmpl raveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment 6 b6)o,ibri.k2au wfvwith a simple pendulum that is releasedkw. ba2bf)urv 6,6iio from the horizontal 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 l 3ferw5 3pos+object rests 2.0m from the center of a rough turntabls+eof 5rwp 33le 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 the object?

  07.19: What net force is n ws;1 qlu- bxzii2++lvecessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on +u1 q -wizlls2ib;+vxa horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an obj0f)l x3tkj0- tpwacnov(svn9au0kgpl / :.h3 ect (mass = 50 g) on the end of an 80-cm string rfa-c.tp3l0 o9)3kjgav px( uv0h/snwn:k0tl otating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m witvjdz7 cq,,e4dh a constant kinetic energy of 128J. What is the magnitude of the net force acting on the massqcdj7, e 4zvd, as it moves?

  96.24: A 2.0-kg ball is attached to a urv/ z9 ch:b2vc cvx)c;u)he z;ll1a10.80 m string and whirled in a horizontal circle ;cvlu9 rzcevb u)hzl:1xccah; )21 v/at 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 of a ropesj+ +z3aip; bp, in a uniform circular motion. Which of the following stateme+ 3 is;bappjz+nts is NOT true?

  00.19: An astronaut in an orbiting space crafx+ lrxxre2* ,1/f-4 n hbb9f t)rlmamit attaches a mass m to a string and whirls it around in uniform cifm)brh are2f xx- 91t, 4ml/rxli*+nbrcular 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 double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the strx( 9oax *i6 crkni.ybch f56u*ing 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 hxf9a*y6c *knc.urxiio(b5 6 when the mass swings through the bottom ofthe arc?

  94.15: A car is travettqxr xu/f 5e:cjw xv h30,34yling on a road in hilly 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 the car is most likely to feel w0ytxr4 /hxv x33qj5etfuc, :weightless:

  17.10: A 2000 kg car mrmfvjyg/5 *0u oves 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 with radius 25 m, as indicated in the figure. Which one of the following choices *u/ygf 5mr0jvbest 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. ekt8q*g95umk/x q--)h mqlusa 4 p+ttThe magnitude of the net fortx p8tek m5h at+*gkqu9q m4)l-s/q-u ce on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest fmd:r- bo/ wcz:rom 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 -m:rd: bc/owz. 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 connectn iea3- r7z4xxed to a string forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly 3azxenx 74ri-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 5.0 newtons is applied to a rubber stopper mmr5w j*9 h a.x9py/ vdz )fpqo(n9,hdzoving at a constant speed in a horizz.(z9fr/hynp *vp ,oj dxa599whd )mqontal 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, connay2j-jdijk hfqn9ri pf+l 8 7op17 j24ected to an ideal horizontal i2 7jf-lh9+dp7oik 8rj4pny q ajjf2 1spring 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 keya2 1o./ds9u t8ewzrg mass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. adzs/1u.te9r oye82 w 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 (labeled X andY) are at reston a horizontalz7-kbx -c*s-maq. v to 5s+zog disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of thvqoa-ckxbt- s.*5 z msg-o7+ze 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 conne mku+2ai6ogw *cted 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 and forms an angle+mk6wg*au2io 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 figy ;tv6yzwj. 5qure. The string to which the mass is attached has a;5.tj yvw6 yzq 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 m35hvvn0-/z uppb9xxuass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its cev5x9 hxp/3un 0p- zuvbnter 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 objectp bs+(xl)v .8jhlub d2 with mass M = 2.0 kg is attached a distance R =1.75 m from the fix(hxs.d 2bp+jb l8)vl ued 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 movcmm/k60 y(i tz;ajzr81myq s0es in a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly 1jmcs0izmm yz;a r6/ kt8(0 qyuntil 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 circge e2c(j -d /f(2/5xsbpx9a: pytpw gale, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved countercl 2g jc-29ppe5/a:b/(tgs d xyxf(wpa eockwise 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. The bucket is spun 0 uze2vx1jqtc 1l ts;7in a verticajs27 uel tt1vzx01; qcl 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.