95.02: An object shown in the accompanying figure moves in uniform circular motp8nujvp2rj 0ij.g39z ion. Which arrow best depictsi8z 0pu p.9jrvngj3j2 the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat (zjs7p3u 9c1:wt weal that rotates counterclockwise at constant speed at an amusement park. At the location shown7cwaws1 uplz j3 9(:et, 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 constant s4l-ez 8to e,gf8-ydpspeed in a counter- clockwise direction. Consider a time interval during,egf-p-4 tdseyl 8 8zo 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 conk f2yw1d ,cjnb r9p45j z*oy0gstant 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. P ,*52cy1r9k wyjbdjo 0pzf4ng oint 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 around the vertical circl 7jakv w0)zr(1jfn-a rpi*yi1e shown. Whick(a 1 i rzjp f7va*)nyrw10ji-h arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a sma( )+ erk y (t:h(v mco4:fetx35mbkrzjll 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 labeled P in the figure, at which lettered point on the path should she let go ofefrv(tr t 3(jm:mh 4oe+kz c x(y:kb)5 the string?

  15.23: A car moves with constant speed around a horseshoe-shaped path as *fxins3) 8z6gw w2ln kshown wigizx )s n 8w*lwn36f2kth the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon pe(l 3er )azs-ibrform an experiment with a simple pendulum that is released from the horizontal position at rest. At iz rls(-ab3 )ethe 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)jrvf7 +m +h8fn point-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The fvf+ rm7h+8j nperiod 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 necessary to keep a 1. 0 kg puck moving in a circle o wi: ;t6szkp(kf (:ztps; k6wikradius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (massrw j(id.6h0yq = 50 g) on the end of an 80-cm string 0 .h yr6i(jqwdrotating at a constant rate of 4 times a second?

  09.24: A point mass moves alongiz(d7qax9*kbl3 d 7fs a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as it moves?kbil* qfa37s7zd(xd9

  96.24: A 2.0-kg ball is attached top xfp,pw7 y85snq0m)o a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution q)s ,p0ppmw 8fxn57oyis:

  99.22: A child whirls a ball at the end of a rope, in a uniform circular motion.j :lo48. ydydb(x9c zi Which of the following statements ioyx9ldj8b: z( d4y.c is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a stringl6rphn 34n 3ge6hvi4o mi7hdf4ln67g and whirls it around in uniforil3 4hnfh4pv3nr7l6 64m67i nhoe ggd m 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 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 bpe +.ksavu+bjdd +y7now .yanj. 6(6it is atbd+y dvkjapy eoas nn+(wu+6 .7j.6b. tached 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 bottom ofthe arc?

  94.15: A car is traveling on a roa)iewfeh x:7j+d 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 thfw7:jie +e)x he car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 5m:gl q2 5egxxm/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 fix 5gl5mq2: xgegure. 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 ci)soemory q 049rcle at constant speed. The magnitude of the net force on the sph 40 )9reqooysmere

  11.47: A simple pendulum of length Lha 15b/yven tk8,: 6f*doh6 o exhmumem)sa 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 the5 ummbdeoe 8): /1k6 h*,6tofexynhvm 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 simple pendulum. The mas-zt e ymw((1j4vs mw1e2woxr0s is released from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the mag (m1(xr2osetm0e z 1j4ww yvw-nitude 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 slk )kz;xom3 :btopper moving at a co3zk m x;):lbkonstant speed in a horizontal 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 to an ideal hot+le-5 k tyun zukkmq.*7sd wgd/n97 3rizontal 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 fornwdu. uygm sd7+e39/lk* ktk- 5zn7tqce 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 mu 1xc0vjiqbyy9,.o tgg ;.h 6n/s in a vertically-oriented circle of radius 0.75 m. What u6 y9.b.yxq;n0t ,h c1igojgv is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (lau;a-hm va.p:r3k b:/5i slbsp beled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and thr3is:-bb5pvp;kh/ :a rsm.au lough 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 conne /id+cz6a6 zwvx hov3c,c9vw 74cp ,e hu6u8cected 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 strivoc iud vvc+3c wwzpcz6a9e,7 h86,6eu/x 4 chng 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 figure. T demhpp j,xx5jc ij,w038aw +;he string to whichj ,j8apmjp0w; h5wd+e3i xcx, the 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 isp -)ottqa io13 qmroym52)xh+ at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular ato q+o )ri o2pxth3ay -q15mm)cceleration 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 hfdnt/ 5e07dq R =1.75 m from the fixed center of a disk as shown in the figure. The disk st/ 0nedq tf5dh7arts 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 initialtyap +) (n: 5bt 1uy,rterll+w speed 17.0 m/s. The object’s speed increases uniformly until it has moy5welt( pt btryua+ r:)+nl1,ved 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,u82 n 0mrw9dq)mx16.u7llqvc zwaxzw3 +,djz starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throq01)x dm27wdu6 +maj .8qvz9cl zr3wwu,xln zugh 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 1l*v1p9 iez gz1(gcsdat 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 in the bucket. Whevp*eid zs (c1g 19gzl1n 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.