95.02: An object shown iflvc t4f 3vh9.n the accompanying figure moves in uniform circular motion. Which arrow best f vh4flct 39v.depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel s1n( s4 ot2rs*ogoq8( mogdy+n eat that rotates counterclockwise at constant speed at an amusement park. At the location shown, o* 4s1ogn8gt r2dsonyo(+ (qmwhich direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular hcq4dw1g yvw oqo8 341path at constant speed in a counter4d 1c4yhvo q8o w13qwg- 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 velocity during this time interval?

  08.15: A particle continuouslfl99 u016mg *c/bs) ozldbyjx y 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 fr1gf/lj o6bcy zxm09bs du9)l* om 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 speed ajbze*693 raavom5 0j lround the vertical circle shown. Which arrow best indicates the direction of the object’s instantana3lbj 9oa 6z 0r5ve*mjeous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a +pny*e )guqhk.z;c)u;tq gj (7 d e/plstring counterclockwise in a horizontal circle above her head. 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 lql 7;+pugd;qnegu y )jk*/.zp (t) cheettered point on the path should she let go of the string?

  15.23: A car moves with constant speed around a horseshoe- :dge-db )m/cu5tsb2f:ck o )mshaped path 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 in traveling frft /5gc2c-sd:dbb))om :ue kmom Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendulum thatrjk7k. iv iim5wnr0l21aeg uz15( 5i q is released from the horiz.laiqr01jrni51mk5 v 75u (zei gkiw2 ontal 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 res fn85wonmjug.8b /:q wts 2.0m from the center of a rough turntable as the turntable rotates. Th:g8o wbn/w.qjf n5 m8ue 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 keep a 1. 0 kg puck moving in atv6 .bb 69ocmx 52,bt0x(eckjp qid8i circle of radius 0.5 m on a horizontal frictionles0 . 86cibbim6qptkebx2vjx5(odct,9s surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (mass = g+u qcj;,8q+2gi v,qiq jxg5x 50 g) on the end of an 80-cm string rotating aqg5,2 +;+q, 8guvjgiqcxiq xj t a constant rate of 4 times a second?

  09.24: A point mass moves along a hori2 .in :m-le (juffti5wzontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass el(- fuj inft2:w.i5mas it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horizskcsi4ihl kw5s7 p:5hwr werd:9b 6:i*o7hi /ontal circle at a constant speed of 6.0 m/s. See figure to the right. The work do irk6s/5c95:hs*i7swrwi k7 whdobp :e4 :lhi ne on the ball during each revolution is:

  99.22: A child whirls a ball at the endm+ij8j gs3m;b of a rope, in a uniform circular motion. Which of the following statements is NOT true?m8s+ g3ijbmj;

  00.19: An astronaut inrarh r we93:c) t3q.t5po2 gis an 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 mass is v, and the tension in iwpstg) rr3qa: 9c hrto3.e25the 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 leng/exr- x6zk s5k40bar nth L to which it is attached makes a 90- /5 4rxaz- bs6kx re0nkdegree 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 swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see fi 5*2p)0(dc)i*kesb qgd nsozugure to the right. Assume the car has speed v and the tops and bottoms of thes( )u5c0qeg i *zs*d )2dkpnbo 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 12k+9;y v, spn ruj7)zfh.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 injf;npy)sh+vz, u79r k 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 at constant spee rmsxg:r(z.1lcetjv 8 ucnpw- *c)o9. d. The magnitude of the net force on the spu9:*rcj nx 1(lpcm )vsw-orgez c t8..here

  11.47: A simple pendulum of length Lhasa point mass M released from rest fm ycwki419pgjtl 04cgz*l - j8 qy,8iirom 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 mapl8 k ji g8lctymjyw410c *4,gi9z-qiss. 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 fow *m*8 )mudj/un zk8ebpo)dt+rms a simple pendulum. The mass is released from rest and undergoes simple npjmo*z /uwk+db*))88 m deut 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 force of 5.0 newtons is applied to a rubber i:mi17jy)1 epu:hakn 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 th1a:nyi mi:ukhj7 p1e) e stopper?

  05.28: A mass, M, is at rest on a frwoxuc1+tl 2;aom 8b q91icoq )ictionless surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm ft oa olium1+)cb2wo8x1q 9;c qrom 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; vh*0 qlby/a jzqxw-hy80lef*l0m ,o speed of 3.24 m/s in a vertically-orieybel/hx-o *qmh0 vzll8,y* ;wf0a jq0nted circle 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 (labeled X andY) are at resabb-o 1jslp/oof2 -t 5ton a horizontal disk rotating/sblptja5fo- 12obo- 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 i*mse -2mf y .fdrmvbi*wx hf .6,m rhy.(h);jfs connected to the end of string and moves about the string’s fixed end in a conical motion with a constant speed of 4* rmfx(mvws,ye; .h.*2b yfhfimhfr) -j6 dm..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 thjocy;gn wun+((2ds z -e figure. The string to which the mass is attached has a len2 cjsowznyg(n;-du +(gth 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 30.0 cm-0;q tr04l9wsa zub bb from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular acceleration of 0 qbwz90 -subltba4;r$4.50 rad/s^{2}$ . 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 dis,.b6 hcyzc yjs6l0)8 b:ydc yjtance R =1.75 m from tdyc .)zbyjs 6 0c:8jhb,6cyl yhe fixed center of a disk as shown in the figure. 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 tov )rs 8cz6b8rkp, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise throuskz)rr 886vcb 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 circle, starting at the top, with 7ggfo3u8 x7q qem ,l4sinitial speed 17.0 m/s. The object’s speed increases uniformly until it has moved coun4 qol,g 8e3xsmqf7u7g terclockwise 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 is sk0x9uu9sex oh ko( +0opun in a vertical circle of radius L by a rope. Wo9sh09(u0xo +uoe xkk hen 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.