95.02: An object shown in the accompanying figure moves in un qj f/qzama.-jlw 1-g.iform circular motion. Which arrow best depicts the net force acting on the obmw-q jfgqa- j 1/.zl.aject at the instant shown?

  05.31: A child is belted into a Ferris Wheel stb7z(u/1:eu l qogx 2veat that rotates counterclockwise at constant speed at an amusement park. At the locatox gq7ev1: 2/ tb(zuluion 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 constant speed i1nq iqt15,5kc een6ron a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P toner51ko6 tq, qcn51ei 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 7byh1p yaa6)na circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular a1 a7h)y6bnyppath 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, s.uc/ ffgc;n constant speed around the vertical circle shown. Which arrow best indicates the direction of the objff;gu, /.nccs ect’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the ent* f6 uuw*o,1 1az9cemvgl:awd 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 twirlinvl*u awow efmg11z ut*,6:ac9g 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 c djmq/7/2mf xeonstant speed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the /d 7qxf2mme/j direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Mw)0up(jr6 r azoon perform an experiment with a simple pendulum that is released from the horiz0( uw)6arpzjr ontal 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 object rests 2. fwp-z:-ebfuqs1 3hr4u zsv 3+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 betwezwz+ rf :fh-eb4 1upsv3-q3s uen 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 pe(ad +7g,hv lquck moving in a circle of radiuse,7 lad(hq+vg 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 ouwe+r,3c.cnnuz:wbm 77w 6w ubject (mass = 50 g) on the end of an 80-cm stringww:c6n 7mu+c zw,ewr.un bu73 rotating at a constant rate of 4 times a second?

  09.24: A point mass moek 6y*q f,kwy6ves along 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 theek y q*6kwy,f6 mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m jf-3m rju.4awstring 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 durj 4mj-a wr.fu3ing each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a uniformqv/99ha vjp 0g circular motion. Which of the following statementsj90vqh 9p/v ag is NOT true?

  00.19: An astronaut in an orbiting p*mnp.xln-+2 lxgs4 uspace 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, an*pn+ x nlm4x- 2plugs.d speed were all to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward unt v rn 3wxkr066*lntsqbd;jp24il the string of length L to which it is attached makes a 90- degree angle with the vertical. The t;q j2r*b40vlw6d kx3pnr6snmass 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 6 vivm-8tlxq4;otjcp97 a)a;y 0nqdj 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 weig n)mda-;lj cajt80p67 49xitqyv;qv ohtless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. At there h+ l(qghx /4;cmhk2 very top of the hill, the shape of the road can be approximated as a circle with2 cqrhhe l;mh(x+k 4/g 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;ksy.zgkt6 q , +cj/2ntjh q1r at constant speed. The magnitude of the net force on the sphere/y t,2q+jqk;n6 rtjhck.z1s g

  11.47: A simple pendulum of length Lhasa point mass M relea y3 w/)fqww7 /vwjwe6nsed from rest from the horizontal position shown. In the absence of air resistance and friction, the mass swings thw e/wwyw7n/3 6 )jwvqfrough 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)?

  16.32: A mass connected to a string formvaw/:e9;jh5zaoz;+lc 5v ipe s a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of the following choices a55;pwavv i cl+j;z/e o hze:9 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 5.0 newtons is applied to a rubber stoppelwu4g/ gm/q2f/n(y tsr moving at a constant speed in a hor/fg( 2us /t/qgy4m nlwizontal 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 +a;ymcup rpq5h1y.8 e on a frictionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from rpq .+1apm yh58yc;eu 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 speed of 3.24 m/s in a ve;r (k(h zlp.hke2xj/z -kfl k7rtically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at thepkerx 7 fkk.lz/2h-kz l(h(j; lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) a2neblf h:/lmc5x7w r*re at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of thewrf*e/b :l52cm7 nxl h 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 f lak;)z0wdy9z 57;7btwfi syend 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.zi7y );wk ylw7fb s;a f5zd90t50 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 cir;z.qb / mf232 ia.r xn owva626jd6eftgu0hjx cular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00j vdx6ai 6 6x2.n.f2wtm oh3 ;/qujagef0r2bz 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 u*k. k(gfo)sj11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest .*)ujos(fgkk about 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 distance R =1.75 m fr;g 7yjyfj ;4from the fixed center of a disk as shown in the figure. The di74j ygy;jr; ffsk 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 spee+u(1k * ofl*n 3jvpyepd 17.0 m/s. The object’s speed increase(pune vfj1o** y3l+ kps 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 atqnu)lj (lacmuf* +l1m-p*w)phu 76zk the top, with initial speed 17.0 m/s. The objecn )ua l l1mml-7h(+w*j qzc*ku6)p fupt’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 :xt6)ab-g s220mjy l 79i6 dwlymv mtdat 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 ly2m066y iv-wdd )astxbmt 9g 2 :mj7lto 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.