95.02: An object shown in the accompanying figure moves in uniform circul 0iw/ :eq6n jhwulg;5)ul 2bdkar motion. h: bun;)d2wj6 0wqiul5 /lkg eWhich arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat th y82f0a7,vfcs ke;b npat rotates counterclockwise at constant spee 2sa;fy7 ,c8nbfv0kped at an amusement 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 in a circular path at constant speed in wj9tn3-mfl7 4nkb3 nv 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 circle from Po3lv mb3 7wnnf9-4ntjk int P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously mo2kz :xr)f 1s mc1 lp.gx fbj::4oc-iveves in a circular path at constant speed in a cr412 b-ijof :)1zfvkpxm::.lge scxc ounter- 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 circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constant s9r-. yxhzze b4peed around the vertical circle shown. Which arrow best indicates the direction of the object’s insry9 z-zb .4ehxtantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a sm 1kr9m*9kvekpj,0wp y all 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 j9,*rw pem91p 0vykkk 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 horseshoe-shaped path as4 v bc(dw,r b ehit9lp-fr(6l+ti.ct2 shown with the arrows in the figure. Which one of the following choices besrvbl 2p,itw(+- (dc9l6fit bcteh4r.t describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experimen 3e+x1zqsvf.xt with a simple pendulum that xqv f31x e.+szis 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 obub:e6lk8 v;cb ject 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 frictilb: 6ucekv 8b;on 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 ujumut.l *k9en/;m5m mo f*ag:, ro d2circle of radius 0.5 m on a horizontal frictionless s/ufue*9t.*kl:mdo2g;am mujmn ,o 5rurface with a speed of 2.0 m/s?

  05.03: What is the centripetal accecd( xd(vzrf-t 7rkrty2 a :7)gleration of an object (mass = 50 g) on the end of an 80-cm string rotating at 2 ((f:v7 ykcgdratt-zr)7rxd a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m c8yh; tp*5uorf0 /w0wnnzx s-with a constant kinetn wf zucr;nwpy *ho/080ts-x5ic energy of 128J. What is the magnitude 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 strr ln+ l070 kcaq1,,gbx eykqr,ing and whirled in a horizontal circa0 xnge 7rky q,,q01k,+ cllbrle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirls a ball at the endpcl24-9arh e5 or -ozi of a rope, in a uniform circular motion. Wh 5r-zeap9 oroic2l4-hich of the following statements is NOT true?

  00.19: An astronaut in ane+h*.o)5sb erfkvq h + orbiting space craft attaches 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 masshrh.*bsq5k+f+ee)v o 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 lengtva0t-esot o 5.gpzl /y3;6qkvh 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. What is the tension in the string sa50 o-ez q6;lp /gvyvkot.t3 when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on alj5cf.gp:ah- /rzq w 9k21vgu road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms ofvgwqp91- r/j k2:ag5 uf. hczl 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. A/gts5u/fh pt- t the very top of the hill, the shape of the road can be approximated as a circle with radius 25 m, as indicated in 5p-s /t/ftugh 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 aheho1 8 dm:eq0t constant speed. The magnitude of the ne:emhdo01eqh8 t force on the sphere

  11.47: A simple pendulum of lengr*e6df 3xc kj,th Lhasa point 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 F represent the magnitude of the net force acting on the mass. Which one of the following choices describes the rel, 3efj*cx6 drkationship 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.i,2lfg:mexyp 2 1j)lk The mass is released from rest and undergoes sm,gf1ly2 j:eip)2lx kimple 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 point?

  04.41: A centripetal fod: ndj (/ nhtu.fh1gf4rce of 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 i:dhfguhnd(4/ j1. ntfs 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 frictio5y/+vhi 6eh bv0 wzkxgg((j 5onless surface, connected 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 th( ohv0gg+e/6y xzbkij w5h (5ve person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 88ekibh,0 lt r1as,hh 3.24 m/s in a vertically-oriented circle of radius 0.75 bh, 1khs8a 8teirh l,0m. 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 aw/s / r khn5it *;ciwzthx3cpm2-9iy(t 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 ofi/np hwzc/i-httc2;x *w r9(m s3i5yk 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 slg;x m(ad g9t/tring and moves about the string’s fixed end in a cl/x;tm 9agd(gonical 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 i r 6oi6k-ehgbe4ysa *xdjt853s in uniform circular motion as shown in the figure. The string to which the mass is attached has a length of L d sj6i6 ke-t58bhx*yar 4e3go= 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 rest 30.0 cm from a horizontal diskzx* ky+v3 .ckk’s center. The disk starts to rotate from rest about its .3 k*vx+ckkz ycenter 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 distanph)ymu;fc3* * mmlp) gce R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating frommp)m l;u hcp fym*3)g* 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, with initial speed 1-/*lnjeh q 7fso (a4*luans *b7.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle o uonf*/ as(4sb*-l*aeln jqh7 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 top, with inis/ he3jmc ar*7 )6fagctial speed 17.0 m/s/m)r ashjec*cg 6a73 f. 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 time for this motion?

  17.38: A small 2.0 kg block rests at the bottom of a bucket. The bucket ik)jv xut 8 psf/ sxuvij /499 -qan8jsp)77sszs spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, 7vix)q 9jpss 4u fku8s/s7/ns8z)xj a v 9ptj-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.