95.02: An object shown in the accompanying figure moves in unifnd7od.kehxa+ w2bg9/cr2ik r ho7)0korm circular motion. 7a x+c7 n/ kkedro2dr2hw0bg) koh.i9 Which arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel s9s;rvh noywq.3(i2xv eat that rotates counterclockwise at constant speed at an amusiw(. v2 sxnr ;hvyoq39ement park. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves ingg -ph0eenn)( 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 poin-h )0en(gpegnt 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 s xoa6:mtuljaq 2x.l ;qp.a5k)g 1yb:lsz 69l moves in a circular path at constant speed in a counter- clockwise directi bqo6l1g;z xp2alsx5.6:. skayl)j ma:lu9t qon. 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 circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves cd5t c, ff bu6rr:2;wmnlockwise with constant speed around the vertical circle shown. Which arrow best indicates the directi m2wn rdub f,:;tfc5r6on 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 strgvem v r+a4: svn4da05b y-(lwing counterclockwise in a horizontal circle above her head. The figure shows an 5+w4a(0:vbdvs4 ygan- r emvl 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 constant speed around a horseld r lnnkdo7qx d1 2syu:(/c8,shoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direond/k uly8ln2 :xrd7 qcd,1s (ction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with 0szpa4c eb 0+6tb4aroa simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagrams0p+ c6ab 4oa 0tzebr4 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-lik:;a4 snts0 kwbe 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. Ws:bst0;a 4 kwnhat 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 ;jwt;6 tari.2euu y ,lin a circle of radius 0.5 m on a horizon6 wiauu,; tjly.;er2ttal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) onu/:ydbnxu g *1 t5wtl(cd4p. w the end of an 80 ywtld4w:b.1n/5u g(d *pcxut-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path o xep z1;fa3uno:ram4+ f radius 0.8m with a constant kinetic energy of 128J. What is the magnituer3oxuz a4 mp;:a+n f1de 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 horizontal q3rtzcd g/ / /7zm(jfecircle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revejr/3d qz(zm7gf// ct olution is:

  99.22: A child whirlzs zuh r2slqiip 4 -x:0cq)e- ,3bmqt5s a ball at the end of a rope, in a uniform circular motion. Which of the following statements is NOT trueqhs p)i ib-0 e-rlzqq, c 4t5z2ux:3sm?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a strinx3+pu cev,r 9fg y*t/+ jqd,kqg and whirls it around in uniform circular motion. The radius of the circl*,q qg/ 9dyp 3fx+,jrkvteuc+e 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 lengthe-d; 1oaff e,f L to which it is attached m;eea o-f1f,fdakes 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 the mass swings through the bottom ofthe arc?

  94.15: A car is travel 7e .f5u;qzzw*fujv 0z j7w/jking on a road in 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 f7vj. fj*7u u ez zwkqzj/;0f5weel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s. A,6data4 8/iv)r: jsz v1sda wft the very top of the hill, the vz/8j)6: a wisfdv1drts ,a4 ashape 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 constan1-3bryzan gmq.a*3nj-3 ad rwt speed. The magnitude of the net force on the sphere1r.yag-nd r3*3-b j 3z qnwmaa

  11.47: A simple pendulum of length Lhasa point mass M releasekj xz3ua)/ ce,b4g9ixd 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 z)jx3 c9ig,u 4x /baekmagnitude 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 txqs k, rknb8k89k 3/lmo a 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 3km8nr8s l kbk/9,xq kpoint?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber stopper movingh(wncr8,mwzrn l ( stru 1:.5n at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smas( (5n8m1n:nuwl .,r htrzwrc ller, 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, connect 55nfvra5: spzwsga, yub7 14red 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 necs55a fn7 1y4zgrb r, asu5:vpwessary force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 k6t uc.y-o;0c3p0y gbyqlsx h,,4xwm)xpow x( g mass with a constant speed of 3.24 m/s in a vertically-oriented circle qwmxoxcpg y ) p 0lu.(0;3,xbtxwhs4o, y-6cyof radius 0.75 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 horiz3o(j gq 5bq wnpq:3-vzontal disk rotating at a constant rate about an a :g-o(nwpzqq3vjb35 q xis 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 massvl+f2lo 9qtcx-qru e6)jf7 8j is connected 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-rfqv)q9u lxfej8726 clj o+t/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 s7yc7bl-c yj2b0elvc0hown in the figure. The strijclvc0c by y0e -b27l7ng to which the mass is attached has a length 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 atqueup((59(i tvy) y 3yxu*b6xv - nhqb rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular acceleratiopteq nb- uviux( 5)*b 3(u9yh6(vyqyxn 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 withyd1p*vxm g9geigp8 8 7 mass 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 disk starts rotating f 8de my pi9p187gggvx*rom 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 circj/ q7weimh w7e5ov1b)le, starting at the top, with initial speed 17.0 m ov/ebje)qwm5w771 ih/s. The object’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 final speed of the object?

  16.40: An object moves in a circle, starting at the top, )f d-+9tg2kwwv vpeo ps e5)r2fw//t kwith initial speed 17.0 m/s. The obtkg-pks5v2 frpewe2/d/) ) t9o+f wvw ject’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 at the bottom of a bucket. The bu 4+lwm7p l jwzp;q 7xbu)g+m,jcket 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 g jl+7, 4jwp;blxmz 7qmp+uw) 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.