95.02: An object shown in the accompan,6dvo s2zw2p vj;1d6 mk lgg-pying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the object at the instant showdjws g2 pk;-v2dm6 z, vplo6g1n?

  05.31: A child is belted into a Ferrb0ra1xe c yruf ye(;e5tz*-+a ea fl)3is Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best representax e0 ;ruzl cy5-e3aye1ebfartf ()*+ s the total force exerted on the child by the seat and belt?

  08.14: A particle continuously movm0u/feyj 2po8+ dkyvp9b3bl4 j:zh c 9es 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 the cc 3bev /ppz+jl9dm80j fhyby: 94k o2uircle 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 at consta.* hxwhhp0, ohnt 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 the cir*h,ow.hp0 xh hcle 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 vertc3) o5mvt-;owl: qggxical circle shown. Which arrowqwo5mc 3;-)x:gvtolg 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 txpcz,qfka bd z4)n6r7+*oa z)he end of a string counterclockwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewebk+zz4r)c ,7pna* f)zo6ax dqd 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 horseshoe-shaped pathwp n7bl(t0e ),gr/q xx+dvh5rr) bjz 2 as shown with the arrows in the figure. Which one of the following choices best dest r0wbxz5x ,2bvq7j d l )/rhrn)+g(pecribes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on t8qbq 4y *ldq9ihe Moon perform an experiment with a simple pendulum that is released from t4q* iq b89lydqhe 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-like object rests 2.0m from the centeriyz*jt4fi87l tn.i.cqq+ z ( x of a rough turntable as the turntable rotates. The period of the turntable's rotation is 5.0 seconds. The coij8xzl (.*q7z+ .t4yfti qcni efficient 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 k6g363fga zmew ;uki l5g puck moving in a circle of radius 0.5 m on a horizontal frictionless surface w lazwekgfu6g;m3 6 53iith a speed of 2.0 m/s?

  05.03: What is the centripetal acceleratio/ hs5y 4ik,dthsn-o2/oeu4mxn of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a second?x, -y4k2/s/mhnuih 45 sedtoo

  09.24: A point mass moves t e*ge,pvq07m along a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on theqvt *e ,gm7e0p mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and whirled in a horizontal 5wx9ar yspc ov gf8.+,circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball dxc,9 +wos8 r v5py.faguring each revolution is:

  99.22: A child whirls a ball at the end of a rope, in a un: g/0 ssk0j23 *aqp,o ynpw5gmk5nnlhiform circular motion. Which of the followyg/nap h53 250snm0wklqs g* p,njo:king statements is NOT true?

  00.19: An astronaut in an orbiting space craftl 9bpxk s(qyc7l)+km, 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,k 9)c,x(ls lk qby7+mp 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 it isi;t4svjanav1e 8 sy46 attached makes a 90- degree angle with the vertical. The mass is rtva4ysnivs 4j8 6a1e;eleased 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 figure to the ri(a ;w*nr+ a: el6( ykjkwibk5jght. Assume the car has spw e(liy6kk+:wa*; k a(bjr5njeed v and the tops and bottoms 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 over a hill at a constant spu e1d6pf74zjj eed 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 represents the magnitude of the upwa4761zd pejfuj rd force exerted by the road on the car?

  97.13: A small sphere is moving in a vegmrl(3c-j;zxs f( +qortical circle at constant speed. The magnit3;go qczsmx(j+-fr (lude of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from66yg s ,kvp,ii 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 fksi,,g6 i6vpyorce 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 to a string forms a simple pendulum. The mass is re0jd g.5ib w3meleased from rest and undergoes simple harmonic motion. Which one of the following ch5beig mw. 0d3joices 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 stopper moving1p;u* srat hlv6(ou8zlkw 9j:rx (w)v 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 tx9a;rv( )uko*wv: s( huwjzp8l16rlf, of the stopper?

  05.28: A mass, M, is at rest ov3xy.4yin mapgowc q7+1v 94 un a frictionless 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 brougn4 4ov9.wc3ia1py 7x uymqg+vht 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 k7h:,.t,dmt0gvgbajo +nn; 4j,tdu zu g mass with a constant speed of 3.24 m/s in a vertically-oriented circle uo.,;7gjhm :0 +tdtb , n,aj4gu vzntdof 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 czz4e84svip 9 xzofg0 hl4t dacw:1w14oins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicucdfzzve104i4w p:sh8z 9x 1lao44wg tlar 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 sb:q1 g3roe aysy vle2 k,v5:f /y-a6qc3/jqs etrin1 o/f l,3:g5vqkyqaas-/yy3eqsbv:ec6 e 2rjg’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 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 mo3 eha8xz;3-,) epgtkw.v ws potion as shown in the figure. The string to which the mass is attachedw)eekhsowp,8;xgta3p z-. v3 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 cn0*/v1o*y . n3 eg2hicp cbmucm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular accelvbcno 3u c yg2nhc1p0/ e*i.*meration 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 wi62i lxq46f +efohv9jywsqh+ 0th mass M = 2.0 kg is attached a distance R =1.75 m from the fixed center of a disk as shown inl04 6 6 f++2si xjweyhovqq9hf 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 circlt /y*frt4 0v jqrmkc*rnx- 1+de, starting at the top, with initial speed 17.0 m/s. The object’sctnfx4 /r0y j 1-d tvr+q*mkr* 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 circle, starting at the top, with inioii )6o o,qwdja0rr1q().qiq0 4tfid tial speed 17.0 m/s. The object’s speed increases uniformly until it q(q0a)iq ioorf4r)0.6odi dji, q1wthas 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. Tle.c 8zse4p8 mhe 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 remainepezlm88s . 4c 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.