95.02: An object shown in the accompanying figure moves in uniform circular moti*jdkcnp w8 md9 l(:nz2rca27son. Which arrow best depicts the net force acting on the object at dmpkz(2ca792 ljc d*s:n rwn 8the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates couekm6.i)5fj7s f*f fv/2e+oq)o- s h qwouzw1 pnterclockwise at constant speed at an amusement park. At o/ 2fs)f6sq j*5f- 1.hwp qo)eziw7+kfouvme the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuo dcpl/m 9ri :zmp/-s,rusly moves in a circular 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 pszrd/pp:mcmr i/9l,- 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 a circulagb) dtv8ya i;rb;*.hw.z.irt r 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 point Q. Point Q is exactly half-way around the cir zyr.t; *bi8b.g d)tw;r ia.hvcle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constant speed arousswx(: ht95.g xqio w+nd the vertical circle shown. Which arrow best indgh:9 qwsi w5x(+xst o.icates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a smpi +sg8pm+vh m 3n t,2xguu97call 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 froch7 m2+gtsniu 3,xm vpp+8u9gm 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 of the string?

  15.23: A car moves with c2ym ol: mjc(,vonstant speed around a horseshoe-shaped path as shown with the arrows in the figvmc yo(l:mj, 2ure. 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 perform an experiment with a h4.kq y.ncihf1p.-ho j/ , wvosimple pendulum that is released from the horizontal position at rest. i ohh,hkn j./f qpw1yo .c.-v4At 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 kgqep r6j,/ tti+9:t:p ris 7nivq3;hyq) point-like object rests 2.0m from the center of a rough turntable as the turntable rotates. The period of the turntable's rotation pq:9tietyqrns7r:;v /t+ i6qh3p ,i j 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 kee -4n )fqpvnnf6p a 1. 0 kg puck moving in a circle of radinnf 64nvp-q)f us 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of as-ok1hjxvg sj384 8yxn object (mass = 50 g) on the end of an 80-cm strino8gyskh1 s4 xj8- vxj3g rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a ho2sg /hyi 4bpa,rizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the maghbg2, /y ispa4nitude 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 in a hn8g)rc n87jtoorizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolutiotjr8n)co g7n8n is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circular motion*:u6gjqi, tlt1mjf m-. Which ,m:fg6jqm ttu-j l1 i*of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attawj 4qshdfs (m;d5-.d;m 8jdbdches 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, an5qs ( jdjm wd.mdddsh4;8fb -;d 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 thhb-zj;82dm xf a-f7 zge string 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 a2 7-jm;azz8fxb h-gdf 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 tows5j7d (nmot/kuka .7 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 feew j(otk7 daum/.7k5nsl weightless:

  17.10: A 2000 kg car moves over a hill at a constant syus+.du(h 7 wj:er)y-94whvp t -abf cpeed 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 u+ wawfd-.c jyhsbt)-e py(v49r7 :hufollowing 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 ma-wi2wkqpg4 b dnx:o 0ar) 1wl8gnitude of 2 i04d gl ar)8qbwpowk :1xnw-the net force on the sphere

  11.47: A simple pendulum of length Lhasa pointh5ng. km:anv o) 5kcg04w7u qv 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 5.wm h7nag4g qo50 uvvn )ck:kF 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 k e)br5.jw x640 gmgzea string forms a simple 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 mass swings through its lowest poi6 k.eg)0bjxre z4gw5mnt?

  04.41: A centripetal force t 95 wvorkdd(6of 5.0 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 smallekv dt9rw5o(6d r, 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 iemh;3e :x:m /z 4qcltw5g :ptan 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 sprinmmthe: lwc;5/:z gtx4q:3eipg 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 jw)*b fww* jo-8tet7s3.24 m/s in a vertically-oriented circle of radius 0.75t8t*w *7)-w jjewosbf 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 (labeled X andY) are at reston a hormjvvhnn 7)++ f(w2tyr izontal disk rotating at a constanj2(v+vn)+ 7ynr mhwft t 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 string ntg 846,;nrro19c o sgqbaz )dand moves about the string’s fixed end in a conical motion with anoqbo)ad4;8ts,1n9r 6c ggz r 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 motionv-(pex*cys3 n as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m andv3py*n c- (esx 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 horizontal l: ezjhxwnpne 6skc*v 47,;y0disk’s center. The disk starts to rotate from rest about its center witk*sv6:;zxplw e7h ejy0nn, 4 ch 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 = 2.0jk )n/ w3zbo4ik*s +tc kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from res/z4kbi ctk 3njows+* )t 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 1( hre5 hd3tywa 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 angle oft1ye h35 d(whr$55^{\circ}$. 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, ww ,rrg)(226csy5-mk d-za x 2jbntpckith initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle o5sa-k,2z2k2 g-tmrcnb( yp d6wj)xrcf$55^{\circ}$. 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 k0krnk6r457 htx9:o8vyq g mvxg block rests at 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. When the bucket isgv:h 5q8x0yt6kr xr n 94okv7m 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.