95.02: An object shown in the accompih4u7awwof3b5v 73zy9-f oaq anying figure moves in uniform circular motion. Whicha3qy 3u-7aof vhw95 fiz4o7wb arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a i(vz 2uid* e*pFerris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on the child by i v*(p2*udz eithe seat and belt?

  08.14: A particle continuously moves in a circular pat;3m i-)xiy h3b tfo1roh at constant speed in a counter- clockwise13xr) ii mo-o 3fy;htb 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 velocity during this time interval?

  08.15: A particle continuously mo) n qoifx4up t7a8;.w zpzjm,ig9/h(wves 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 ti9n7mpo ga ().4fzuhx tpw8,w/z qj;ihe circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clockwise with constant speewm2i+v -nh3su d around the vertical circle shown. Which arrow best indicates the3i v u-2n+mswh direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls am-8tpkv 6m6+7nzgzkf small mass connected to the end of a string counterclockwise in a horizontal circle above her head. The figure shows azn+ kzf-67vgk6tmpm8 n 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 conscn)vayn5 nvlx, v ,ba;);:bz gtant speed around a horseshoe-shaped path as shown with the arrows in thnvg;) ,c ; xv):yaz,bblva5nn e figure. Which one of the following choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moonc(ng * 2bi 0rbwkb9*ji perform an experiment with a simple pendulum that is released from the horwbk9(ic**0n b2j i gbrizontal 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 object rests q yr7hd,k f+0k2.0m 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 +qh 7fdrk0 y,kfriction acting on the object?

  07.19: What net force is necessary tb r-ckbj l9cu5)(6dfvo keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface witdf( vbkr9 -c 5b6ul)cjh a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = 50 g) on th: spbdmc,3v7wjl h-( ne end of an 80-cm string rotating atjl pc svbm(7:-hn 3w,d a constant rate of 4 times a second?

  09.24: A point mass moves along a h7jaa:4ttn5i i+z (vs vorizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitu:inv75t+a vatisj4(z de 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 st-794 k j2f tfs.9.xqgollxm bsring and whirled in a horizontal circle at a consta.sq4xs ll-b.o 9 g7kff m9jx2tnt 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 end of a ropeh9 4; b-l9o8vb,e+ovu(8xg8x hbbax bsu qfh9, in a uniform circular motion. Which of the following statement;h+xub f8gvxsu ,b qhheb(o8b8vlxb-9 o 949as is NOT true?

  00.19: An astronaut in an or x+ij 51bgr-rci9j42fy1lzxq /xfj8qbiting space craft attaches a mass m to a string and whirls i8b xj1 gc9 5/qir1-qi2 x4fjrzxfyj l+t 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 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 to which i1 qpum-n)kf*, /d qzog 4+nfwct 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 str fu)+nc-,wd*qmnp 4z kgq/of1ing when the mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see fx10; .x: jwzaenwhzq y-.yda6 igure to the right. Assume the car has speed v and the tops and boa x- ;n1z6:y jdw.xze0wh.yaqttoms of 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 o p- hm:pof9t8wver 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. Whi -8:p9ofhmtpw ch 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 i 4 v+sgbm;zgcmu -sl97s moving in a vertical circle at constant speed. The magnitude of the net force on the sphereg+zm7u4 vcb; s 9gm-ls

  11.47: A simple pendulum of length Lhasa point mass Mc5nz*tyj auwu3m5ry-/xyv15gx4 b.l 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 represenb5x-/ *ytrwu4amy jcl3u 1yv.zx5n5gt 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 to a string forms a simple pendulum. 4-jow(*mad,qm+ 4ru q 1zbb6 c:pwxhiThe mass is released from rest and undergoes simple harmonic motion. wzqx64*:apr- iou1whj4 +m( b, bcdmqWhich 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 is applied to a rub.2jvvnxkz/:52zgk+a * 5qtc l1sjsqqber stopper moving at a constant speed in a horizontal circle. If the same force is applied, but the radius 1jz*qsxkc2+ : v /z an55kg2vsj l.tqqis 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 an iayv;:kw+-bgeh vfj*,y/ma ro 4w 1oq7deal horizontal spring that is upstretched. A personbog;7q-+hjvy4r /,owva:mfka ey*w1 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 the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speed of3hw6r( 7v s3fv qu;jmdgwaq 12 3.24 m/s in a vertically-oriented circl aw s;wqjuq3rfhv62g71v(dm3e of 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* hhx72qvwi. o-c+3ndwem:e6ax) v qw (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plan:vn *7eqw e)vohihcd 3w. xmq2+6xw-ae 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 connectedazxk7+ym eg3 3 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 m + x3gek73azylength 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 aln y15s0u)t0: a jcypl:(vbishown in the figure. The string to which the mass is attached has a length of L = 3.00 b5y0yl0l: u(svctpj aan 1):i 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 horiz cx-r38ctkmu-vr +. jcontal disk’s center. The disk starts t+v km r c.r-8tj3x-ucco 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 from slimwn9j 02v (,j vr8wthe fixed center of a disk as shown in the figure. The8jrjlnwv0( mvsw2,i 9 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 to. jf 5 eda.-sx9;uqpjup, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throupjfs5;u.e. -q9 duxja gh 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 cir ;*t;n2tv,n fz( ruyb0d,pefl cle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has movedfv(ft*yb 2,l;utze ,p;rnn0d 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 resthp-h itx.,q+:)r sdes s at the bottom of a 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 : rhexh-s,i) qd.+ sptin 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.