95.02: An object shown in the accompas59u/xj4zu;kebo bb, nying figure moves in uniform circular motion. Which arrow best dek9jbb4/;sb u ,xz ue5opicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rota f9a p *3m;v.hn9gdaqot:xk(dtes counterclockwise at constant speed at an amusement park. At the location shown, which direction best representshv: tg*(.am9n d;koxaq9df 3 p the total force exerted on the child by the seat and belt?

  08.14: A particle c8c y/rpyro) xx)(gcg.)m 2q zsontinuously moves in a circular path at constant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circula/y rxyzxpsm2o ( 8qgr.g )c))cr 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 moves in a circular path mnuki 3wo tr)np r; +n1e jot4)za+jkr/w 9)w)at constant speed in a counter- clockwise dire4/)e) on+wurjkorn k3rti) t 9w j;pn1wm+a)zction. 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 acceleration during this time interval?

  15.07: An object moves:na7y6e utw;d;; coxu clockwise with constant speed around the vertical circle shown. Which arrow best i;y: e6xw;at7u co;n udndicates 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 string counterw-df,4x qa5 uyclockwise 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 go5uya,fdx 4- wq of the string?

  15.23: A car moves with constant speed around a horseshoe-shaped path 9udyq07x.(0r)elois n6e m mxas shown with the arrows in the figure. Which one of the following choices best describes the direction of the average acce 0miy 7 e6xxo0lde n.uq(ms9r)leration of the car in traveling from Wto X?

  08.35: Astronauts on ) cpmuef9 su8a/,q8ycthe Moon perform an experiment with a simple pendulum that is released from the horizontal position at rest. At the moment shown in the diagra p9)u8 cqe ,f/amcs8uym 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 restio *xd) 1d,tkjkm ra7:s 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. W)tkx : d o1rjka,*dim7hat is the magnitude of the force of friction acting on the object?

  07.19: What net force is necessary to keep a 1.u d;rekx2-y9g g*k2(ohx8 +p*ehl8f )od jl hv 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speeux- e gkoh+** x(elfg)2k 9d r8 dvhjlop8h2y;d of 2.0 m/s?

  05.03: What is the centripet07.fmb a)zazd al acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a secfa.) dbz0zm a7ond?

  09.24: A point mass moves along a horizontal circular path of radius 0.8m with ahyqor7bvl-xng7;w+u)) t / s j constant kinetic energyvhg7y7l+)x t-ju bn o;w srq/) of 128J. What is the magnitude 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 strinps9g x) 26yzoeg and 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 rop)s6zy9 gx2e evolution is:

  99.22: A child whirls a balb wb4i;0(gkhaxl ; f*pl at the end of a rope, in a uniform circular motion. Which of the following statements ig(;alb*i p4 w;0xbkhfs NOT true?

  00.19: An astronaut in an orbiting spaceppqxj ,zi 8rv 932pq8ie-fmo8 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 all to p88evxp joq-iq32 mr zf,i98p 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 woo7h9ew0/ehy 1loy zc 7( of/xhich it is attached makes a 90- degree angle with the vertical. The mass is re9ec (w/olohyx oe7y f7hz/01oleased 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 hilvvaf z i)o dy)k1aq.(xy 0mh83ly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curv aqi y(h31)mx 8z0)dkf. yaovvature 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 12.0 m/s. At theq it(47lh c*;0r)zctsk g d,as very top of the hill, the s) t,tq rg*k;cc isd7hz( 04lashape 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 the upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant sp);yhzl4 mxd ;7eiho j1eed. The magnitude of the net forced7o41ie)xyhzhl;m;j on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from restdid2j04cu0hyv lb u7nb1q7g : .ze2ph 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 m.uh7c 0 p27gl2d qj1d evzn uib:4ybh0ass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simp -5f236x evsm mxqyo)syk5 g-)ts pdy)le pendulum. The mass is released fro spd o))xkt-m 56e-5smx2 s3vyfgy)q ym 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 point?

  04.41: A centripetal force of 5.0 newtons is applied to a rubber sto3i5qlleofnc, e om8+ ;r (csm;pper moving at a constant speed in o;;rscqm,i3+5m(co f el8e lna 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 the stopper?

  05.28: A mass, M, is at rest on a frictionless surface, co2dl ) apz3pqqg*m:5c tnnected 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 brought back to equilibrium and the mass connected to it is now dqt:cg3 mp 2p* 5d)zqlaoubled 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 swings05bpk8f. t4zt -blrwy a 4.0 kg mass with a constant speed of 3.24 m/s in a verticallrb tt0f84-y5 wb.zp lky-oriented 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 (labetucvl qp;-v p/ k7ntj+o8/au nt;8wz/led X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and thvu n/pj8uto8tawtvn+q /l/7-;k z; pc rough 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 thkfff6,l5+ +tnbvb vo6e string’s fixed end in a conical motik + f+t6ffbnobv5vl,6 on with a constant 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 uniform circular motion as shown ij / y euaspn/b-eo8ft2 lj85(wn the figure. The string to which the mass is attached has a length of L = 3.00 m an-f2wy//5e jb 8aostnjpu 8e( ld forms an angle of $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mou yxl unjh(4x3ypp9 3tz i;;-ass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from (-x9pny;;zy3olpju t4uhxi3 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 a2)aws8 q*qzjx ttached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with consw8szqja 2x*q) tant 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 i-e14) 5vclnd i-c ynmff *)qsjnitial speed 17.0 m/s. The object’s speed increases uniformly until it has moved coun -cfl- v14 eq jnf5ndm)c)i*ysterclockwise 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 initial spee6y2d( m d;v*wog7 giqqd, sx7qd 17.0 m/sdmq sy v 7qw;(*qgi od62,x7dg. 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. Thvn800 qma x8kv.*(fswuuluw 6e bucket is spun in a vertical circle of radius L by a rope. When the u06880wx.(m nla uf kqu vs*wvbucket 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.