95.02: An object shown in the accompanying figure movess 9m*vxy8*y dfh bh9d8c. e0ox in uniform circular motion. Which arrow best depicts the net force acting on the object at the in9x808 h xcy.vhbdos 9e*d*fm ystant shown?

  05.31: A child is belted into a Ferris zjetg;yj5w() Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents thee;5y)g wjtjz( total force exerted on the child by the seat and belt?

  08.14: A particle continuo366p 7) ,pcapffk+qyenzxdc 2lm:z3r usly 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 path from point P to point Q. Point Q is exactly half-way 2nlqd)pzf7apf x6,p :cyzr 3+6e ckm3 around the circle from Point P.
What is the direction of the average velocity during this time interval?

  08.15: A particle continuously moveswrcjb:)sup2(* ( z6 6f*-ihxlbkn r hg in a circular path at constant speed in a c:h-x6* fb (n* rk h6iwzsrj bug)(pcl2ounter- 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 circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object moves clkw7gmgw/yt e,lb7 fx* 2*b8 gbockwise with constant speed around the vertical circle show 2*eg7fblw7m, ty8bx b *w/gkgn. Which 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 string counterclocl ly67yt ume:)kwise in a horizontal circle above her head. The figure shows an outline of the mass’s path viewed from above the twirling mas y yelt7l:m)u6s. 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 path as y8bmav z(p3;i1i rs.6wl* bbhshown with th*mb b1(lav6p .r;yzii bw8h3se arrows in the figure. Which one of the following 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 simplq9za 3)39x z6 spfu/o6qhsah ye pendulum that is released from the horizontal positi3z f6sh9xy3pq /h)uaoz a9 6sqon 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 center of a ro8 uiqy-x5 o*p;j,p evqugh turntable as the turntable rotates. The per;euxi, opy*p8vq 5qj-iod 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 acting on the object?

  07.19: What net force is necemea9uv+qov-,, ..xqhv n2y- epzj;d2u xtr -fssary to keep a 1. 0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surfav2-- he,xe2 p-umd xf.yau n t,z.r +vqjvq9;oce with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (ma s kcp(bdl7he ff,e4 3ob9.o3jss = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times a secb(coe4j ls9pfb.f keho37 d3,ond?

  09.24: A point mass mn3 jp y6pj3+am gc,g)boves 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 the mass as it mjn+3 )pg, j6yabcgp m3oves?

  96.24: A 2.0-kg ball is a4ee o-iu2ss 9w6c cux0hp3xla*/ldt0ttached to a 0.80 m string and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the rix*c3 90-swp0tc seloulh6/xai4e 2 udght. 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 5e: +d fmdhxe8uniform circular motion. Which of the following statements is NOT tree5m+ d hxd:f8ue?

  00.19: An astronaut in an orbiting space craft attaches a 7wx4(w1u yw7 kky1m u. nlcut*mass m to a string and whirls it around in uniform circular motion. Th*u7 uwy n mlwxkw1kt(74.u1yc e 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 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 whicywr :ao(hzl) 3h it is att:azyo(whr 3)lached 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 mass swings through the bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, sw 73ek n cu,h)v54 mrrs5avu)tee figure to the right. Assume the car has speed v and the tops and bottoms of the hevanm)ur5)sw7u 5tc ,kr v34hills have radius of curvature R. The driver of the car is most likely to feel weightless:

  17.10: A 2000 kg car move6tb,mi f /vx0ls over a hill 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 represents the magnitude of th/v0, mftix 6lbe upward force exerted by the road on the car?

  97.13: A small sphere is moving in a vertical circle at constant scdpfx-c ci(*44jgy4q peed. The magnitude of the net force cxqjp 44-(gdcfc4yi *on the sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rest frot0 q 2 szei3ow6n/u7ljm 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 choiozni 2t 3leu 0jsq/w67ces describes the relationship among these forces when the mass swings at the bottom of the arc (point P)?

  16.32: A mass connected t9qnart6 qur uj:/+tivhf73k5o 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 h7ia9nt/kt5rr fuq+: q 3vj6utension 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 imp/8 omf0vxr5s8 (x2fcfe 2 ysp e))vstopper moving 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 f, of the stoppsfm 2fv8x8i pevo/ mp(f0sy)cexr5 ) 2er?

  05.28: A mass, M, is at rest on a frictionless surfacj 3 tn8sb,2gduos- .zv k3edfinps): 1e, connected to an ideal horink:s n bgvd- i28, d1)fop33sjetuzs. zontal 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?

  12.22: A girl swings a 4.0 kg mass with a constant speed opyr dgyo.95 s6:mz0cgf 3.24 m/s in a vertically-oriented circle of radius 0.75 m. py90mdczgr 5g.:y s6o 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 andY) are at reston a horizo id /a*5hbej70o x2+bmhyb ov8ntal 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 froo*e7vay+hb0h 2obi 5jdx bm/8 m 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 stri jnh 1g-dvzdr88q.q 5nng and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The strq8-zd gq 1jvnhndr 5.8ing 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 xo;zw)a s 1uy lvw1y6/circular motion as shown in the figure. The string ty;zlvsy)wwx / 61 u1oao which the mass 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 zn m, 78q anq,*vyy+fjo.2zt a30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest about its center with a constant angular acceqzynqmovt ya 8.j7 *2 +f,anz,leration 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 attached a distance Rg+ ,s*+yze -qnyl4ab(my5( 1u tefxs l =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rest with constsx,fzq s llmtg ne15ay-4y+e+( uy(* bant 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 rqr87j je9 vr)npy9q7 ;(kht qec+(au top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise thjq(7p qnu(tacqy9r;rv+7jer 8 ) he9 krough 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 1 ft5 bk8mdzpu382v lmthe top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through af zm l2mupdb5813tv8k n 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 bottxrtx nh)pt-uhrd9u 97aix-6)om 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 t7ntuu hxrp-a9)r- i)9dx h6xthe 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.