95.02: An object shown in the accompanyy2uh cmum-(p.:6zau o ing figure moves in uniform circular motion. Which arrow best depicts the net force a6m-myh(uc:ao uuzp2 .cting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwise )t q(etfpkc0cxk13zyjf 0gw 6;id :m-at constant speed at an amusement park. At the location shown, j)zt :0 mq3kic1tef0(6xcgfkp-dw ; ywhich direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle comehhvoi 3 9831e pwda5ntinuously moves in 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 Q. Point Q is exactly half-way around e33 5hp 1dwiae8o9m vhthe circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuoun9a2t+.k6ov rvc0, *zor cokdsly moves in 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 p orc6oa+r,*v dk9v. to2c0nzkoint 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 around themhk :cjiwtalw/:edm : g8/6c5: k* edu vertical circle shown. Which arrow best wtdej:m5*/c c: hl8m:gd: u/aik w 6keindicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass cona75 rj1midg,g 0 bz(mtnected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from j7rmggt,1ib d z m0(5a 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 horseshoufwk0c;exl8p ,ih6t yh;7d+oe-shaped path as shown with the arrows in the figure. Which one of the following choices best describes the direction of the averageexk;o,hw 0tu7pc68 f+ ld y;hi acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple paxhq o,*7c1o/ ;root-4q c 4rhkh7iopendulum that is released from the horizontal position at rest. At the moment shown in the diagrhop*7cq4ao r7 -o4 r,hikot/;hx c1oq am 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 o. 3)iqilz ,fhff8i*s2t aog v(bject 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. What is the magnitude of the force of friction acting on the object?sq)l .fz2tgii,8vf i3 a (*fho

  07.19: What net force is p,*rtx,)u ,5nwfl ctjnecessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m ftpwnr5u,lj)c,*t ,x on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g)jkzm o.b4auyk 592(qs on the enq5k km9(s2.4uz yjbo ad of an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path ofih4 dv oy683wj radius 0.8m with a constant kinetic energy of 128J. What is the magnit hv yo3ji48wd6ude 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 jq3l o8-(ewce whirled 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 each revol -lqewcoe(8j3ution is:

  99.22: A child whirls g(6uao,n4 byva ball at the end of a rope, in a uniform circular motion. Which of the following statemeny4,6bg unvao( ts is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass 6dkjxkz+8i*..dkvth 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.x68* i jdh+zvk.ktkd 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 strin3( yk(8nc, wfeqgy (pjg of length L to which it is attached makes a 90- degree angle with the vertical. kn(p(g3 ycj(w ,e8fqy 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 traveling on a road in hilly terrain, see u,bhs; 68)pnvx dgbw,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 ,d;pnbb h8 ,)6gsvux wto feel weightless:

  17.10: A 2000 kg car moves over a hill at a constant speed of 12.0 m/s.77z3n qxn6n+ttr c(e4 rp ,eguvtu*2n 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 n7 763 ettnen puvnr, (2gqz4* cux+rtthe upward force exerted by the road on the car?

  97.13: A small sphere is moving i 22w72decrd *cjqtx; qn a vertical circle at constant speed. The magnitude of tx 2r2qj qcwdd; *2tec7he net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M vo +5u:;vl w z8s cy7z)wjrexpz/ )6trreleased 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 relationship among these forces when the mass swings at w x/5w )l zz z+)vpe ;vsry786rtcu:jothe bottom of the arc (point P)?

  16.32: A mass connected to14kgtcjua7 n( a string forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which akjc(u1g n74 t 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 force of 5.0 newtons isrlsin+(6y+ /ltp. dzc applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius is made smaller, what happens to the speed v, and the frequency f, of thtci + yr(/s.znl6d +lpe stopper?

  05.28: A mass, M, is at rest on a frictionless surface, connected to an idealmh *z2hua) m7s +g9ldh 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 the person to hold 7h+m 9m ahs)h ugz*dl2the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 3.24 mj d :o/zcj )-xehxs:+b/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass-xhsdze)+xjbc: / j:o when it is at the lowest point of the circle?

  14.23:Two small identic zg0imkcu1q9 z2;vlm 8al coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and through its center. The dista2qmi9zvkcu lzg08;1 mnce 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 connectum98e fri-6x ted 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 and forms an angrft9x6-8 mei ule 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 dq35ypvz av9 :the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of qvdvzya39:5p $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0 6kqxf4q yse*32bgo 4xg is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate f* f6syg q 4xqo4kbex23rom 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 =1.75 m from s f 9((ze yb:0i,avxxpthe fixed center of a disk as shown in the figure. The disk s:x x9sb,f(0vyi(ze a ptarts 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, with initial s p(m,uoqgy-(dpeed 17.0 m/s. The object’s speed increases uniformly udp ((uqog -,ymntil 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 hb.g 3moiu7ctr,*)xyro +;/k*mvck c a circle, starting at the top, with initial speed 17.0 m/s. co 7xk+tv*hcmy3/)u rob; g,.cikm*r 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- n/mgmu d-hmq:46ci4nnw .xg . 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 the bucket is at mghd6nq mg4x .n4/-unm-wic: 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.