95.02: An object shown in the accompanying figure movesr;sg o 4ka*e*o7yen2gc1 :woi9pwct) in uniform circular motion. Which arrow best depicts the net force acting onrtgyo e71* sokpngowe c;w*9ca ):4i2 the object at the instant shown?

  05.31: A child is belted into a Ferrf (-3mprxxm1xb,6kl ris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the locat fxpkbx xm6mrrl (-13,ion 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 in cymqz 4g 28d5qa 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 exactlyq42dymz g qc85 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 circu(9o4o oqkkn ps0za, i(lar path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves alo 4zoi((k sno0kop,a 9qng 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 ) crxkkgh v/7+0jq-ec gsnoh b)w:g96clockwise with constant speed around the vertical circle shown. Which ar/sk9bhk) v jhx-n )reg6:0 g+wcg7qocrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a stri tyey0sa ly36,ng counterclockwise in a horizontal circle above her head. The figure shows an outlinet 0,yy3lsy6a e 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 of the string?

  15.23: A car moves with constant speed around a hp f e/ptt)fh4wgz*a,hf0+s(v orseshoe-shaped path as shown with the arrows in the figure. Which one of ths)0f+4pv hap, /wetgh* (fztfe 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 m:a m1wizx /a *f hv/:.wp21eu gugah5an experiment with a simple pendulum that is released from the horizontal positionmxvww pi af /h:g: mh1*eauu.1/z5g2a 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 t6s9qlyyttw17cc8+ ; vzv d .gkg) point-like object rests 2.0m 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 between the object and turntable is 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the fgtqtlv .wc zcvty68d7s+9y1; orce of friction acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck moving f/,xwc2g:bkx in a circle of radius 0.5 m on a horizontal frictionwc2/kb f g,xx:less surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceld*f7mrpku.h e dqgt f0a1b2+9 eration of an object (mass = 50 g) on the end of an 80-cm string rm0kfd.2pd + 9ebr17 gqu htaf*otating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0q66. enu lq/lw.8m with a constant kinetic energy of 128J. What is the magnitude onw/lu 6q l6eq.f 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 whir1)yaqauk2e4etq 3v z*p pdq-; led in a horizontal circle at a constant speed of 6.0 m/s.k *qpaud;pteaqz2 v) q3-4ye 1 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 rope, in a uniform circulfue(z,np5lo,gp,x+ i ar motion. Which of the e,xz 5ln (,,u pipf+gofollowing statements is NOT true?

  00.19: An astronaut in an orbiting space craft attach+(a 53+ta pcfwc tbm9hes a mass m to a string and cwpf5+a +hbtc (ma3t9whirls 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, 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 l2 -t3tkk9)mgyhwq+r b ength L to which it is attached makes a 90- degree angle with the v-grkbk3+t wh29t) qym ertical. 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 to k(q6n 1)pzxca6wvbm /the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of wkpb 6(1a6vzqn) /xcm the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. Atons) /.;18m 7g uqya45)m ;nmxfgabszc 3f tth the very top of the t8sh;;mbot)m1ag ug7.5 xf a nfcsn4qzy/ )m 3hill, 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 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. Th uvnk92 k,o-cdu,/u aee magnitua9,uu2d- ou/e,v cknkde of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest;/uge*ml 0-p at 0ywt+bwn ca56tub /r 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 5ypwg+a /tu b6 *nu 0e -0;tawtrlcb/m 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 xey3; v*tj;r osimple 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 ityjot ;;rxv*e 3s lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopperp3 tlia* zhidv/sb0 c )bu/23n moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happens to th 2lvb)/iihz p303 an/c*t udsbe speed v, and the frequency f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, cop f,w16q+mxaz2(g c)qm rrp4mnnected 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 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)r,pz1qmragx (cpw m+ 426qfm 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 vjdoxr l85 xd*qixb2(,ertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when it is at the lowest point of the cixq*ol(r8xb,id2j 5d xrcle?

  14.23:Two small identical c27o3,6tp: qr+jzlxztlt 1gse oins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The distance of the coins from the center of disrsj7,eg tl2+ 6px 1zlo 3ztqt:k 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 :rbh )/v btlo jt9ac(7string and moves about the string’s fixed end in a ohv/9 l r(t j7)atcb:bconical motion with a 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 unifowl;8 lanu:j4 xrm circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms alwl8 ;4n jaux:n angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mnd7q8hirr i84,sa : ty,w;gg bass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to royrh 8, w8 qd,: ;tg4inabg7rsitate from rest 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 m ,i.lyv i0sxec6 u;i)kass M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The dic6v .,uiisy0i xk) l;esk 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, wi: vvkrmg0;t2 dth initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle o0v; g2krv:mdtf$55^{\circ}$. 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, witv.mvrhdaq03 h6+mlxmum 1 88wh initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throughvm w88xm3.u q+mahm1v rdh60 l 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. Ts+v8))dyk pkknt(6m ihe 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 tk)6m +iyv(kks)nd8pt he 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.