95.02: An object shown in the accompanying a yc nk46,k1:c5m2p xbdqop9nfigure moves in uniform circular motion. Which arrow best depicts the net force actiybakkqx6mn d oncp5 ,p2 94:1cng on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat1i6n3i5 h nwli that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by the seat and 5 w1iinh3 6nilbelt?

  08.14: A particle continuously moves in a circular px1 /* bhnw6ob m(nrwepnq+kfg+ p6 *6:wzvyc6ath at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular path from point P to1w(gnn xb z*m :6* wfpohew+c/pv6ky6+6brn q 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 tplo u+nh 8ontk7et.3+ip t .-moves in a circular path at constant speed in a counter- clockwise direction. Cons87tui3 p-en.tk lt +n o+hot.pider 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 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 aro hex4 dul8/mof,3/c ixund the vertical circle shown. Which arrow best indicates the direction of the object’s instf ol8d/x mu/3hi e,4cxantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string counterztedh1- ulw hd)g(py1 ol0 +/kclockwise 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 tohwkzydol0u h(1d) e1g/+lpt - 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 arovlsm-0zm e :g .w.tsp( x;y;gdund a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of ;wmg lsg t(pxz.vs:0.ydme-; the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum w . i8uyerrcwa b1a8 knap33 m;m:a33hj 46htythat i 3 8anmm3 by6wwhc13i.ay ;u4:rjkaera83 hpts released from the horizontal 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 2.0m fli8cq.s 0yi1g:b4e r from the center of a rough turntable as the turntable rotates. The period of the turntable's rotati:c1l4i.bfg r i8e0 yqson 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 qi9 .vahk;3te moving in a circle of radius 0.5 m on a horizontal frictionless surface witq9i; ea.3tkvhh a speed of 2.0 m/s?

  05.03: What is the cen4/+s t*cugilj 3qw5gp69ym zrtripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating amgj /5 p+z6tlrq9 3iygscu4w*t a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m wit+aov 5tug,w:kh a constant kinetic energy of 128J. What is the magnitude of the net force acting on theuo5 w:tg+k av, mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled *ef8 hx0rvfz+ 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 e+re8z0f hfvx* ach revolution is:

  99.22: A child whirls a ball at the end of a b .l1yol(uy kq63z9wzu+ bqa6**mkrqo x*x g/rope, in a uniform circular motion. Which of the following sx zy9gou mla*(u/*+*qkxkqbr6w3oqz 6b 1.ly tatements is NOT true?

  00.19: An astronaut in an orbiting space craft attacheb :uka36f1x3m h sgbo2 6kx(rzh l17grs 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, and speed were all to double the tension required to maintain ubh 6 rs1kmulx7:z r31x(2bg fo3a6hg kniform circular motion would be

  07.22: A mass m is pulled outward until the string of length Ls g1p0 yxx1pgl1lng ne(7l05p 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. What is the tension in the string when tgg lg17lpn(1s xlp nxey05p10he mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the right. uy2q ph ;zxb(18w .u8f- mdmtrAssume the car has speed v and the tops and bottoms of the hills have radid ;mf 8zhy pxw2 u(8.qm-1btruus of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill atv)fq6bl9mg bpi2( vl4 a constant speed 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 (q2lb mf l)b6v9p 4vigfigure. 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 it fg:9z(vvz g3h* n o8xo08dxms moving in a vertical circle at constant speed. The magnitude of the ng:3hozdx 8x fvg0n( v*9zotm8et force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest ff 61 r;ulebt(8pvvb)vrom the horizontal position shown. In the absence of air resistance and ; bet(rvfl )1 p86uvbvfriction, 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 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 pendu0s e3/;bi dylnlum. 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 mby0id e ln;/s3ass (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 ru b6ua.m7 u0gfubber stopper moving at a constant speed in a horizontal circle. If the same fu au6b07 g.umforce 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 idealkuh;f 17e5mdno ll+nn;r ;p)n4abab( horizontal spring that is upstretchpn+ obebf5ua r n1d7; (amkn;l;)l4hned. 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 to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg malfyzmms3jl 475ws c0 () 5zqgfss with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mq7 0mzf5 cs5j (4gs3my)l zfwlass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at rest2qe 83c +o6(7yroy/zfsj mxeoon 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 cozx2f(e 8s yq3/re m6cjy7 o+oenter 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 cd b 8wqzzx.6o) l ikm*u87-wxionnected 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 string has a length of 2.50 m an-kiuxd ilm8o x*7bwz6w)qz8. d forms an angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in ut77 bxrn g4dh0zio)p+niform 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 an angle of 0 7px+id4zthro) 7 bgn $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g istgs7vrz3 v+bx j68:j2 +acpbx at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest g +cxzv p6jtb:vj r87a3xb+2 sabout 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 63frj9q2mx h tattached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from jq32r fm6tx9 hrest 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 speely )l(bbte*kk14d*li d 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angll(ydi1 l bt)keb*4 *lke 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, s5rs.*q bfs+aq tarting at the top, with initial speed 17.0 m/s. The object’s speed increas aq bfs5r+sq*.es 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 at the bottom of a bucket. The bucket x jza:j9ke409w5rcpq is spun in a vertical circle of radius Lq9w:0x kpacj49j5r ez 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.