95.02: An object shown in the accompanying figure moves in uniform circular i sut; n93shf4 0wa*/teqjes)l+oms4motiqhs)t4 *ots9amuse s0i ;3e jl4wn+f/ on. Which arrow best depicts the net force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotat)zujo.l cu1 gxq;z : r91beem3es counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on 319g 1morqu. bx;) :jczuezel the child by the seat and belt?

  08.14: A particle continuously moves in a circula4kj pu16njzy et9/6zlr 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 izulyz6 j9 e41tp6kn/j s 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 y m9olbhn3 4b *z05dnepath at constant speed in a counter- clockwise direction. Consider a time interval during which ze4l*n9bm0oy5dh bn3 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 constc1 bcg-; jpx0gant speed around the vertical circle shown. Which arrow best indicates the direction of th1 c;-g 0gcxpbje object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass connected to the gkhm5t+,1bifko q5swhl2e s, jg-5y 5 end of a string 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 gi-2hw +5bieg5ml qy1,t5 ks,gfshoj 5k rl 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 path qh8dozl +no63as shown with the arrows in the figure. Which one of the foll+8 lzo 6o3nhqdowing choices best describes the direction of the average acceleration of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple penxo4p:gyz+(m+nx qgv2 da- m;y8jy - dcdulum that is released from the horizontal position at rest. At the momc odjyyx y2v qg-a+pz;n-d4 :xg8 +mm(ent 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 d2i 8ha3herf7of 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. What is the magnitude of the force of friction acting2f7r ea38hdhi on the object?

  07.19: What net force is necessary to keep a 1.qy3v .z8qy8q ux;fr thvw:y8, 0 kg puck moving in a circle of radius 0.5 m on a horizoh3tv x y:yfq ,q.vwy8;r88zuqntal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an objech)- zodn*whlukhbt8 : c(j4+at (mass = 50 g) on the end of an 80-cm string rotating 4hcuht+ abzl-* wd):jnok(8h at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of w--mg8)qc mca( :s ktlm-2obrradius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on the mass as :c(q2 o)rb8 ckt -msg-ml-awmit moves?

  96.24: A 2.0-kg ball is atlum6sx jq/z6 fo0e8(ptached to a 0.80 m string and whirled in a horizontal circle at a constant speed qfu /p0jo668 (mxelszof 6.0 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 mot57:pc fp7aol6c/0sopn 3w wj yion. Which of the followi7aonflw6ppsc/7y 3o p :wj50cng statements is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass mmt t01l8h2xss/e vpfk *s2(lx 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 th flps lx1*ks82( sex/h0 tv2tme 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 outj tkym -:becm6 avx+,9ward until the string of length L to which it is attached makes a 90- degree angle with thm+6at9j,x mvb-ce: kye 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 o dny8m+8kck 9figure 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 8 okcd n8k+9ymis most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at a con-. devve:6kct/8 z fxnstant speed of 12.0 m/s. At the very top of the hill, the shape of the road can be v-fvc8nxe. : et 6z/dkapproximated 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 speed. Tf:q5s( o*traal.cx;gxq m( k(he magnitudeqxt q.*axmc(k(f:r;5 glsao( of the net force on the sphere

  11.47: A simple pendulum of length Lh)hfo w n*9gau3asa point mass 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. Letfghuo 9wan* 3) 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 mass swings at the bottom of the arc (point P)?

  16.32: A mass connected to a string forms a simple pendxi 7-be7agkfjcb1nczhee zl k r.)92)g 30c)wulum. The mass is released from resckar.enzz0bf) -9web73ec gh2lkgx )c)7i1j t 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 ihswi7d(f-wtpe(n)k,cy h 2ni4; me ; ys applied to a rubber stopper moving at a constantkpetny h(f 7e2im) nihwd;;s4 c-w(,y 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 the stopper?

  05.28: A mass, M, is at rest on a frictionless 16tui0)ncl 3octgsl 6e:76 pdm y.gwsm r;xr;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 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 nitpxr:yw ;l1m6eog mu);7 d6ts.r6lgccs0 3?

  12.22: A girl swings a 4.0 kg mass with a constant speed of 3.;6 i*zji1tsgko *1 wok24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass whe11*z ;og i kos*ti6jwkn it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X y pjdpb;i3a g 80v6z6i pj k/bv(kgn4,andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of gzi4 akpj,6 8jn bg bv;kpy60/dvp(3i 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 stri7hng)k u;x fm6ng’s fixed end in a conical motion with a constant speed of 4.0 m/s. The 6 fx khung7m;)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 unifort6ynbfpooey.(p l p() h/,,btm circular motion as shown in the figure. The string to which the mass)pfpyo,h6obtt. ( ,yl/n( bpe is 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 cgy ;p8qt4lu :qm from a horizontal disk’s center. The disk starts to rotate from8ptg4yuqq :;l 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 kgii ug3 dcc9-s) is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest csi -du3 9)gci 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 ri*6o o4yhj:ftop, with initial speed 17.0 m/s. The object’s speed increo hio:f j4yr*6ases 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, sta0ia n0yvgtv ky1ay 9;.rting at the top, with initial speed 17.0 m/s. The ob 0vyv.k9iyg1 yta;a0nject’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. The bucket i -btt( d:vvqq2mrosg 4y h-jy,,oq7o;s spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just fa hr2,-(btsovjty qooqv mdqyg:,4; 7- st 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.