95.02: An object shown in the accompanying fst zxmr+e i9b1:gjq2 /igure moves in uniform circular motion 1bsgi2x+te/rq:9 mj z. Which arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belt0vxz 9s;3 zokqed into a Ferris Wheel seat that rotates counterclockwise at constano;k x9zv3s q0zt speed 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 continuou,3zx 4n7iyy cbsly 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 Q7n xiy3c4b, yz 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 m/ lus/8 ;ahgkxf8c3cu7k r*rt oves 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 point8kc7f* ktuluahc3/ /8xgrr s; 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 aroxvesuq ua.w5*/.6r h*kk c6 iqund the vertical circle shown. Which arrow best indicates the direction of the object’s ea/ r x6 *ikcsu kw*vq..h65uqinstantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a string coz7fgvbfc8d h**xyj ( t135mc eunterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from abbzgc d m*yvf8 37xte(ch5*1jfove 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 pah24kmgc8 fjg m7tmh55th as shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acceleration of the car f mgmk5m45872 gcthhjin traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum ,:lb8lxv;y lq that is releasedblxly,vq:8 ; l 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-like9vxja 6s 2y3vx 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 coeffxysa j932xvv6 icient 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 cirw ;7dgv gr7:idcle of radius 0.5 m on agg7r7i dwv:d; horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration joz;- h)8wv fmsy7xy, of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant ratvw y;oym-7zjh8s)f,x e of 4 times a second?

  09.24: A point mass moves along a horizontal circular path o6:y)g /v.)jibn s1uatrw7 ..xahbzwcf radius 0.8m with a constant kinetic energy of 128J. What is the magnitude on w.ubzw7a/j t)is):6yxagr. .1hvcb f 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 whirv/5bms9zbyuv)y )-uk:y ymm+led in a horizontal circle at a constanmuk/)ysyb bm5z:y+-um vv9 y) t 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 aq a:*fed8*w ow ball at the end of a rope, in a uniform circular motion. Which of the following statements i:qfw* o d*aew8s NOT true?

  00.19: An astronaut in an orbitinx r3tj.mk/e h86 c2idug 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 mass is v, and the tension in the string is F. If the mass, radius, and speed were/dje h u2rixt8c 6mk.3 all to double the tension required to maintain uniform circular motion would be

  07.22: A mass m is pulled outward until the stri-s /+ueetli xy4* qgu1bv8tb99mnk/d ng of length 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 b8km4tg-s+y du/1ie/n9tb q vx9 le*ustring when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure tcxqs) :y hj mx7e5;mm/0mmw2uo 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 ;u 0xx) jsqwm72/memmh :5 cymfeel weightless:

  17.10: A 2000 kg car moves over a hi jgpl0-v*ugu i cv;z+/n(pym- ll 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, amy l niu (juv*zg+pc-0 vgp-/;s 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 verti wm 8ax yp00i3;8-*du wogcdqwcal circle at constant speed. The magnitude of the net forceywaud83qg * - 0ic8w;opdwm 0x on the sphere

  11.47: A simple pendulum of let;v-d. +:zy uje-i :gtx-zc llw+w hi,ngth 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 t-::h zt++i, l xeigc-z ;j-yu dlwv.wnet 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 s/tuzncwc 9p lc6xb5*;gufh +1j;hd4 j imple 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), andj jgc5ux 4z9;+blwcd tuhnp;/f1 *6c h 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 movtmd3mrsm 9a0: r0vs/ luc;y3ming at a constant speed in a horil rm;y39c 3 0m:umv0tsdr /asmzontal circle. If the same force 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 frictionles1kpl l0gkic* 7pc cd0v8);tk us 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 sprincl; pd80 u *cl1) pkvkgc7k0itg 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 k7gwtdaw8 x 29eg mass with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is tgx8t eaw7d2w 9he net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andb 6mmoe(pj k;kd m(x;)Y) are at reston a horizontal disk rotatim; omdpkjke( ;m)(b6xng 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 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 about the stringfn/ya4 ci7 m,y:u-a sg’s fixed end in a conical motion with a constantyu: i,sn/f7mac-g ay4 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 uniformk*y:27w + osjhofjd6o 5nb8 wo circular motion as shown in the figure. The string to which the mass is attachn+5o *:7 ys6fkw8oho dbw2ojjed 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 at rest 30.w */uqnq;g; hlog r9h.0 cm from a horizontal disk’s center. Theq.q/ *go;u nrhgh9lw; disk starts to rotate from 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 froua :rx4ma pc*drxz121m the fixed center of a disk as shown in the figure. The disk starp*1 r mduarax2c:41 xzts 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 circl*rh:n5kj dd e/.he,z-n *fap:w t:pyje, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwis5, npn jhy*zw*a.re:j k:/etd dfph- :e 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, with i2 kaofv hkg;,i:cmn5kx/ /j;qnitial speed 17.0 m/s. The object’s speed increhjkg oaq 2v5/;n /:cmxfkki,;ases 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 bb(a+f /-lrtn4v4vhs 8lqn4 a kucket. The bucket is spun in a vertical circle of radius L by a r+tv-/ lfkq4ahn s4 n8va4(lrbope. 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.