95.02: An object shown in the acc,pyiq (0v da4k41y 87mdt jdkaompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the obje4dytjqdkm 81day(4 a 0,ki7 pvct at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates co j0gltpl)*iwd,:fb i0fby;d j (cqk.5tc5+b r unterclockwise at constant speed at an amusement park. At the lo(rjq0lcbi; ,bt05w+p)cb:tl y*dgj i5 dff.kcation 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 pat79/b oine4 nm hq)k:yih at constant speed in a counter- clockwise direction. Consider ao/ qb)knmen7:i4 9iyh 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 velocity during this time interval?

  08.15: A particle continuously moves inx c/l 2-9 kwglk)fyb+m-voni5 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 point Q2lfkx -ow-ky+l/im)v 9b c5gn. 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 constantb)zw*i gt t (j:jtnt)cov;b, 8 speed around the vertical circle shown. Which arrow best indicates the direction ovj t )t*n z;)t igjwcb8t,o(b:f the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string counteubciu +t,6 +p) hnrw8jrclockwise in a horizontal circle above her head.ijr86+tuc+unh )pw ,b The figure shows 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 constant s7 h2ckqha. l1tpeed around a horseshoe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the a .hckq7l2ah1t verage acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simp l,rjqy t6)+f kku/v8:btpv))/ qw pidle pendulum that is released from the horizontal position at rest. )/ pykvfkvui qbq /)6:dt j,)p+8trlw 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-liketrz u46hiqip4q,5 ynq, z; o/u object rests 2.0m from the center of a rough turntable as the turntabl, pryz6t4q,/zoqnu ;4ui h qi5e 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 force of friction acting on the object?

  07.19: What net force is necessary to ko r/ ghb/4zvc:eep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/b//hc:z vrog4 s?

  05.03: What is the centripetal acceleration of an object (mass = 50;um o n+l.9hxxavx4h0 g) on the end of an 80-cm a h40l.9uxn+;xhox mv string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m with a,s. c 5b 78ahqyiam6ag constant kinetic energy of 128J. What is the magnitude of ma,8y gbc q a6aih.5s7the 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 whi iy5*k) obn)ylrled in a horizontal circle at a constann)5)byo*k i ylt 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,hb5krq(n(s2kxj :5e/ zanfc qtl +e9 the end of a rope, in a uniform circular motion. Which of the following statements ite59c q nh2f,5:k q(/(jzae klnsxb r+s NOT true?

  00.19: An astronaut in an orbiting space craft attaches aswia +jyum;j,;g uu xr7h-)n. 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, a.;jjhgu mwu x ua)snyr,+7i;-nd 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 length L ) .d6y szt;fcutavq55 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 the mass 5a .df)5vz ;u cq6tytsswings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the right. ,-p6.xv f+anzizy1zxAssume the car has speed v and the tops and bottoms of the hills have+6iazyp v- nxzf. ,x1z radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car bxj8-2a e1rti moves over a hill at 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 figure. Which one of the following choices best represents the magnitude of the upward force exerted by the roadt1era ij -8xb2 on the car?

  97.13: A small sphere i09(.il 1jto dih 7y rqvy0dv:ps moving in a vertical circle at constant speed. The magnitude of the net force on the spher :v opdh1i0tyy(di.lr7q0 9vje

  11.47: A simple pendulum of length Lhasa point mass kmrp0 + (qko,hM 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 choio(rp,mk0k q +hces 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. The mass is0id0d,l ntqnlxg55 g*) dc1w x released from rest and undergoes simple harmonic motion. Which one of the following choices cor*5)txnqldwd0gc l, x0 gin 51drectly 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 rubber stopper bw-uu :, 9nizjmoving at a constant speed in a horizontal circle. If the same force is abzu:,9-uijwn pplied, 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 blikf1i/y)0 r 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 0 )irlby/k1fi 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 m-t 0hnadfs4k*z e;/mof 5ima 3ass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net 5zmkofam/-e;0*3sd ait n4f hforce 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 restonse9pkor*1;w gnj+ y1e a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its centerw1np9+srekyeog 1j; *. 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 g v epfq)qws-)f wn1(jraq5 31about the string’s fixed end in a conical motq3w1ga5prnws )( qef jf)q v-1ion 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 uniform circular motion as shown in rvm8 k(db83anpe 779fuelm o+the figure. The string to which the mass is attached has a length of L =o +8r8bdem3k9mn a 7e7ul (fpv 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 rest7wt bc-pei.liw;1f i1 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its1piec7-iiwb.1 l twf; 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 = w9.s:7so3k w+dta0rbl gi 1bo 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the f1 0a.w sob dws9: 7+io3rglbtkigure. 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 a circle, starting at the top, witkp iyt(pm0 x14vqa8 u8h initial speed 17.0 m/s. The object’s speed increases uniformly until it ha a8py4 q kx(im8p01vuts 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, startsp ,e2nv e33bling at the top, with initial speed 17.0 m/s. The object’s speed3 pe3be vsl2,n 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 aj(lna9m5j; cpfwf .*h bucket. The 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 the block to remain in place in the bucket. When j jnm*fl5a. chf;w( p9the 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.