95.02: An object shown in the accompanying figure moves in uniform cirj i:d/r/w7l4dv/e9xdjhxp 4y l, 4 wwccular motion. Which arrow best depicts the ,4 ilprww 47 vcled:yh//9dwjx/ 4djxnet force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockcy), fj4ups+ /gd6s*eu we s5fwise at constant speed at an amusement park. At the location shown, which )fuud / syp6jewg+ 5e4ss,*fcdirection best represents the total force exerted on the child by the seat and belt?

  08.14: A particle cont)iv):k6 ovwsj inuously 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 pai v6skv)owj):th 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 in0c( sd ba+ffq4uwy3w) a circular path at constant speed in a counter- clockwise direction. Consi0)qf+ (bsuwy4 wcf3a dder 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 acceleration during this time interval?

  15.07: An object moves clockwise with constant speed around the verticqwg x 21zvi69ez8l3bv+pm:sqeog7 ( bal circle shown. Which8g(me6: wg s zpvev 9 l37b1x2qqiobz+ arrow best indicates the direction of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the end of a strinnmwqg17n0wr f,kf1 z :g counterclockwisnfwz mr0nq: 1 w7,gf1ke 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 lettered point on the path should she let go of the string?

  15.23: A car moves with constant speed around a horse1fu)qs bap v:/shoe-shaped 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 t1:qa uvbp/)fs raveling from Wto X?

  08.35: Astronauts on the Mogv.3ss3wn6z 35 sbflpon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At 5bsnv g3zl fp.3 63sswthe 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 2.0m from the center of a rough;;zq.p4z*i4ipuo -q,c rdi(hun v - oe turntable as the turntable rotates. The period of the turntable's rotation is 5.0 sec u.h4-;-q(uczz iiopnr i op,*vqe;d4 onds. 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 5piqegr,t9s;1qw v5i4,en;nstc so /necessary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionlesve q5w1gn,eitsn; ;54rsq/ ico9,tp s s surface with a speed of 2.0 m/s?

  05.03: What is the cn+zw/re m7y*b;jua: -,t9 ubelsfk (a entripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of7y:/am;9n(tzuwr u *-bks + ,eajeflb 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m ls:y )sq c2a.oh 9tli3with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as 2: ltc9)3ial.soyshq it moves?

  96.24: A 2.0-kg ball is attached g/dry3ea/.u 3k (v i;wjabvj6to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0/rv6baj/iu;va(g3.y3edjk w 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 rope, in a uniform circular motionhxhgy5(9l6w t. Which of the following statements is NOT trw lt( y5hg69hxue?

  00.19: An astronaut in an orbiting space craft attaches a maqa9w j q-8arc4ss m to a string and whirls it around in uniform circular motion. The radius of the circle is rrj8a4w -q9a cq, 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 9pqx,lyf 8ufp0y+)t pa 0thm.wk4g; gthe string 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 string when the m f u8pq a90,4w;y.pgfym+t)k tlxhp0gass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see c8 ufmmd3)i lop3af,jx -5mx8figure 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 likemlp)3 j8i83a fxc,xf5du o -mmly to feel weightless:

  17.10: A 2000 kg car moves over a hillskkse ;g5z42sn:yb b)d7y l,a 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 represegs;, bl)ky5y a:4kzes2s7ndbnts the magnitude of the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a ve/hf,kc jp i(jt3++qvfgm4js9rtical circle at constant speed. The magnitude of the nettfi3vcsk jjqh+,(p j+g9/m4 f force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest fr i1gw u(;j3oriom the horizontal position shown. In the absence of air resistance and friction, the mass swings through the arc of a circle. Let T represent 3wj;r ugoi i1(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 the bottom of the arc (point P)?

  16.32: A mass connected d *d3uqyd7q6c to a string forms a simple 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), and the net force acting on the mass (F) when the mass swings through its lowest p6c d7u qqydd*3oint?

  04.41: A centripetal force of 5.0 newtons is applied to a ru v9mk d, edww/dj uhkz7zh/ 5,7i .oilsw(/(itbber stopper moving at a constant speed in a horizonww(d 5 ,m w /di.,i7el(k/sotz/uhh7kdz9j v ital 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 frz: iu*qy6e)wy q 0bko9ictionless 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 spring is ey wb: *qi90qyzouk6 )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 a1d jn gokowjmul9yo;u 41gr n8q10,z, constant speed of 3.24 m/s in a vertically-oriented circle of radiqryjlzon11 gmn1w0g;,kuo d j9 uo4,8us 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/b-haqosqvlr 0ua;zhn52 g9 ( 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 distance of the coins from the center of disk is relat(0z ru5h hg9val2 -asqb/onq ;ed 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 ,zjawciq z b2sq:db52o0+ rw0end 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 foq +d0a:w zociswbr2qj zb02,5rms an angle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform *,q+t6bvlzbn4wuru- circular motion as shown in the figure. The string to which the mass 4n, v+ ub6rlz *qwut-bis attached 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 30.0 cm from a horizontayih mdk/m3 v*)l disk’s center. The disk starts to rotate from rest about its center with a constant angular acceleration ovd/)h3kym *im f $4.50 rad/s^{2}$ . 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 distamy (4xc/64rzxl+ eo zunce R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with c( /r c4mx6lozyuez+4xonstant 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 initialvl1e* .z w.y7va mvb 5hzb r)uv*xo/6u speed 17.0 m/sm.h7 yvb 5vx r/ua*vo6vlbweu zz1*). . 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 final speed of the object?

  16.40: An object moves in a ci vtycvoy6*re3rxgug4 6(:i; 1mx)qj orcle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an anglecgirv4 jm g3 o66*yv )1;ey(txu oxrq: 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 ),2te:ati wu fbottom 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 in place in the bucket. Whtt) ai,2:fw euen 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.