95.02: An object shown in the accompanying figure moves in un:lel0hp3kq wa9s 9a 1kiform circular motion. Which arrow best depicts the net force acting on the object at t3w9s 1a 9ql0 pkel:hakhe instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwik)z5stao s b/.se at constant speed at an amusement park. At the location shown, which direction best reprezosb /.ats5)k sents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously mnfi 9ig, uednsle4d ;3zq2 :-loves in a circular path at constant speed in a counter- clockwise direction. Consider a time inteeiedqgl;n9sl uz,2i3fd- n: 4rval 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 movv.4-xb.voaljn t4s1fes in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particvasvl. 4j 14 .-ofbxtnle 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed arouxa9i(zb kmw96h61+znq n 8mii nd the vertical circle shown. Which arrow best indicates ab( +x68nzh i ikmq6wiz19m9nthe direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mag14 qc5ud -u5enf/cogss connected to the end of a string counterclockwise in a horizontal circle above her head. The figure showsgdfe5c5 ncu4 o-qg1u/ 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 of the string?

  15.23: A car moves with cm*d;*3xglsja d cx0 bi-w: f3bonstant 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 thwm 0gb 3dj-f* cx;a:bx3 ild*se average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform afw ),zvk l8 - /xkgal+sg0c:zvn experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagram wit: x0/gskzwc ,vl+g- l vz8afk)h $0^{\circ} < \theta < 90^{\circ}$ , the total acceleration of the mass may be directed in which of the following ways?

  03.19: A heavy (2.0 kg) point-lcu0q /lxeq9s;7b 6qnwike 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 kinet en0/cuws7ql6bq ;x 9qic 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 circyi 0e46nzj4dnfr,+uj 7*rvlt0 v sy) ple of radius 0.5 mey6) nrv j04 *,d+zj4syrtfpv0u inl7 on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the celbvbxun iqj285hl. 2 (2hc:cxntripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at anh2icb(xxb. 8luj2vl 2h5 c:q constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular 2 lwtv.g)m 4ih2qz66ulyzn;uyw.2tz/ pq g 1spath of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on tiq. g2 t wp.m 61q46 uz;g2)ln/2su zzwhltyyvhe mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horizontm0qi,kav:ty v7lvi;ya.v0 e/uy*4faal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolutiony vk/vmu.0qeayiv7,*t:i;v a40f y al is:

  99.22: A child whirls a ball at 6jqf :k* ;mtt/zhm0di the end of a rope, in a uniform circular motion. Which of the following statettd/*0 z6 :ihk jqmm;fments is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a y ogdyp ml;x31/ybmx- yarwf1*-(p7 f1toz a8string and whirls it around in uniform circular motion. The radius of the circle is r, the speed of the mass is v, and tm;b1m t*zap fyx-ofr3p-8a/1x yydy g w(l7o1he 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 t6dgo3f) )klvlength 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. Whatd3v t)go6l) kf 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, seep,se*b( vq nto ;+enu- figure to the right. Assume the car has speed v and the top;+pqsu*on- nt,(v b ees and bottoms of the hills have radius of curvature R. The driver of 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.b7k 7xrledha36, /xc m At the very top of the hill, the shape of the road can be approximated as a circlex 7dae3lrmh/x7 bk6c , 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 uuf gpkgf+ ju k7mth7q1.,;4ta vertical circle at constant speed. The magnitude mguu 7,utfhf4 q.k1 kj7+tg p;of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass wezlj 6e4 164p-y5xeqfi/pad:a g,x gM released from rest from the horizontal position shown. In the absence of air resistance and friction, the mass swingsqi -e46p 4l a,yxjg/fewze6x1ad5 gp: 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. 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. Th)+;b - o60qe qui./,bzoghptuu vr 4ize mass is released from rest and undergoes simple harmonic motion. Which oner)uu0- bz;qb.4+p eu iqo/t,zov 6hg i 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 point?

  04.41: A centripetal force of 5.0 newtons is applied to a 1z vzkjxstnj miom,7* 55d9p- +s4nhk rubber stopper moving at a constant speed in a horizontal circle. Ij s+,9oinx5 45sdvm7 z1mznpkkjt h-* f 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 id*-7w 4y04 h fuh2puo xfmsq4fkzd qo9;eal 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 extendem2q-hu4 47uy0 h f*zf 9odxkqfws; 4opd 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 ofh;ydgxmuu3-mp rb9i -5 ttp.2 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force actit-rt 93dhug5u.yp x ibm2-p;m ng on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at ols bki- xj7;3ebe+a)reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and throks;b7eo )lxjae-3 + biugh 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 and moves abou gpwi t..25(5rpqunzlciz2-mt the string’s fixed end in a conical motion with a constant speed of 4.0ti. 5qi czr 2p(n2m5z-.pguwl 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 motion as s*. 3c4pwu waox3 -sqwfhown in the figure. The string to which the mass is attached has a lenf3pwuco-ww.* qa3sx4 gth 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 is at a.+ulb4v3 jocrest 30.0 cm from a horizontal disk’s center. Thev+ oubac3 .4jl disk starts to rotate 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 mass M = 2.0 kg is attached a distance R =1 w5xo wtox 09or :(f1ma.50qrkj kx6kq.75 m from the fixed center of ax5(a6ktr0k oo: 1 w 0qk5ofm xr.jwq9x 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 moves in k l1 gg- l:flhl9jxkv/ +ouv(-a 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 o9- k +v(lj: l gfloh-1ulvgxk/f$55^{\circ}$. 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 tr marw ebl+usfc16yc 0a/f1,+op, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise t1ca u lm, se/+ rfawcf1rb06y+hrough 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 bottompyb6c7ld6 9a9cf,h6kn g5 qqlwu9 b6i of a bucket. The bucket is spun in a vertical circle of rgw ,b7ipfkqlh y96a9 6 d56c9unblc6qadius 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.