95.02: An object shown in the accompanying figure moves in uniform circular gww)zem w 9 c2:kz/7himotion. Which arrow best depicts the net force acting on the object zwmw k9 7izcge2:hw)/at the instant shown?

  05.31: A child is belted intfe 2ut)ne0 5bxkmm: a.o a Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total fork:efam2 nx5 u0)m.tebce exerted on the child by the seat and belt?

  08.14: A particle continuously s9v*5v/m -cuvbb a)jqmoves 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-q- mbv9/5*v)ucjav s bway around the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moves inj egf 52z)5s) r67tt wtv5xach a circular path at constant speed in a counter- clockwise direction. Consider a time ints7rth)5v2 tx5aw )gz f65tjc eerval 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 wkrb6 f- u4)qm5wxd s20spxm* clockwise with constant speed around the vertical circle shown. Which arrow best indicates the )s fu mqw-xx 6*02b4psdmw k5rdirection 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 countwm3r29-yzuc uerclockwise in a horizontal circle a3um c 2-w9ruzybove 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 constantv7(ae z2m 5pmb speed around a horseshoe-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 traveling from W b5pea2m 7(zmvto X?

  08.35: Astronauts on the Moon perform an experiment with7740fzvjaz55yj upbt)ziixf zk b719 a simple pendulum that is released from the horizontal position at rest. At the moment shz)0 5 791jbaipjxzft5zuv47yi7 fbkzown 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 - hga)bb8vnx8zs h47*sz-xl uthe 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 7 v bzb8uhxn)sa8*4- lghxsz-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 nece *ex9 fbj rh0hiz;)j1zssary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface wir z1hj9i *f ze;)jbh0xth a speed of 2.0 m/s?

  05.03: What is the centripetal acy d1x- r uj 3hwj(8rg3;4pqkdkceleration of an object (mass = 50 g) on the end of an ; jkg3ru3phqxdj1(dyk 4w -8r 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of radius 0.8wxqfky 3 i9v-s*47pu gm with a constant kinetic energy of 128J. What wqv*3- 7kxp u4yfs gi9is 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 stt* *nojqm;dherw1 3gjz +y7k ,ring and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work j+g d1 tjmk nhq*oz;3,*7rwye done on the ball during each revolution is:

  99.22: A child whirls a ball at the end of a rope, ikmzpu g/(0;u*9o ya2 dqy*rvwn a uniform circular motion. Which of the following y vmau w(2;*9z poru0dy k/*gqstatements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a strin,n) . d4tx,oltmdr*nog and whirls it around in uniform circular motion. The radius of the circle is r, the speed of the mass is v, and th*dr. m,nt4tnxlod)o, e 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 pujah5jm1 cbrrzvp ig0r6c4 .4+lled outward until the string of length L to which it is attached makes a 90- degree angle with the vertical. The mass is relzv4 6r0 jg+4arbjmiccr1hp. 5eased 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 kg3 r-q b3qv:ba road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills haqr:gkb3bq- v3 ve 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 r /4g3 qacr2 zad)foh)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. of/2grq) rh3daca)z4 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 8* q f3,n13tb y(i0k nylslnmpcqzw +8vertical circle at constant speed. The magnitudeqbw8cm3p + ,01i8n *qk (nsylzlft3ny of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point zzl s(mqvm f71j-ai. ,2 zarr++j5fxhmass M 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 re-m.m5+fx z ijash+r f,j2( aq7z vlr1zpresent 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 to a string forms a simple pendulum. The m+x a2,2mt zmmkass is released from rest and undergoes simple harmonic motion. Which xm2+mk,a2 mtz 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 ne.0,3k :5viab9dfbbjvzvf1 2)va , x 3t tmmntiwtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force if 1 v:z3.tvbam b,tvmd3knb2 t0 j 5,fivax)9is 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, connected to an idensoi;,dfh f 9h -w u6/bm1agp4al 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 doubled to 2M. If the spring is extended back 30 cm from equilibrium, what is the necessary hn-;sidbw1ha9,4f/o ufpg6m force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant de( (r.:.ay//mg rky1ipa w(kh.hfxu speed of 3.24 m/s in a vertically-oriented circle of radius 0au rm dhk 1p.f (khg/(x(yyera /:.iw..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 Xch434+5 -e k*43kwpm9 bwinl.clv)ywrvya wb 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 d9-4p y) n5bkl evv3b cl*.mcwwha4yw3rw4 +ik isk 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 ab2l. tmyhr29ef out 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 rl2 y2mhetf 9.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 ci9j*yvj,krw*c5d ,l zqrcular motion as shown in the figure. The string to which the mass is attached hy*zr5, 9 w jkqvcj*,ldas 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 lfds3si,tn z9j m 04nd-9h1aj of mass 11.0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest hjdm,n1t49- ld3 iaj0sf9 zns 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 =qr3+aq :p/ jtx 2.0 kg is attached a distance R =1.75 m from the x pt:q3a+qjr/ 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 top, with initial speed 63 banm8y p*ic17.0 m/s. The object’s speed *m 3ypbacni86increases 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 initial /k7/qhl ;x .khaduy(aspeed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwiseuq da;h(/lx /.yak7 kh 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 spi++,dukbl gq: /6e tk4axw9whun in a vertical circle of radius L by a rop:kd9w6 h4e itaklbu+/gxq, w +e. 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. 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.