95.02: An object shown in the accompanying figure moves in un9daz7djnc ;f. iform circular motion. Which arrow best depicts the netj fd.andzc79 ; force acting on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates coun5dv w6ru+gnjm+g)i+dterclockwise at constant speed at an amusement parkv dn5+gwr+ 6gd+i)umj. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle contidbvzpm5t. 1y +(z, fw06 s+d2grnotvrnuously 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.z 1v(56gryvn, wdzdpt f+ombs2r +t.0 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 pk0 +7ojsk d6y/(qt qhhath 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 po doh jqq(7t/ksk+6y0hint 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 constant speed around the vertical circleqd8/ 8z bie z3.tyju.q shown. Which arrow best indicat/8z3yj dqbu8q .tiz.e es 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 counterclos5 pih :e*; :nh+0wuuly s,hefckwise 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 ,:e fyu5hn;ul s0hs:ei*phw+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 withz)kj 7s*m 7abp constant 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 travelingaz )* sbkpmj77 from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple penduvran mz5eo(uuzs++: (yqx:y 5j)w9n llum that is released from the horizontal posit qwr) 9+ v(x e:s:+yauyjz(un55mno lzion 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 vca)vg/l5oqv 16wsy 3rough turntable as the turnt/ylao 6qgvv1c5) sw3vable 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 acting on the object?

  07.19: What net force is necessary to keep a 1. 0 kg puck moving iny-ek f0m 6 95twis.yrv)brkl- a circle of radius 0.5 m on a horizontal frictionless surface e)t0fw 5-isyvkb y9 6 .-rmkrlwith a speed of 2.0 m/s?

  05.03: What is the centripetal acceleratz: 9rjx8rept; ion of an object (mass = 50 g) on the end of an 80-cmrx tjzpe; 8:r9 string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal circular path of r2u *z+ndvh e1aadius 0.8m with a constant kinetic energy of 128J. What is thzvu*dnae1+h2 e 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 stcd/7l6/9tdi+ xn( vyin+anr cring and whirled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The w( r/+6v+/txnniccd7nid 9 al york done on the ball during each revolution is:

  99.22: A child whirls a ball at the e3k.1frbks r; 7)bck twnd of a rope, in a uniform circular motion. Which)1 sck37r.wbf kt; rkb of the following statements is NOT true?

  00.19: An astronaut in an orbiting space craft attach :4iy:4ry8 u nhqkz;ules a mass m to a string and whirls it around in uniform circular motion. The radius of the circle is r, the speed of rziy44 :8q hk;lun:uy 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 pullexf9)p 54rdismd outward until the string of length L to which it is attached 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 fdp i)9sxm5r4 bottom ofthe arc?

  94.15: A car is traveling on a road in hilly terrain, see figure to the right7wp:1u:,rkqnfcse t ;. Assume the car has speed v and the tops andfk:utrnp c ,;1e:7qws 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 speed of 12)lp;ynv-y rqo 3 :yi1i.0 m/s. At the very top of the hill, the shape of the road can be apnr yv-i)py1y q3l;oi:proximated 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 movic( s,k:( u 4rsos0nrqd(kuxs )uw.)b eng in a vertical circle at constant speed. The magnitude of the w ))kr,b (u oqxu(:c (.dssekn0sur4snet force on the sphere

  11.47: A simple pendulum of length Lhasaoivfr4f8j: ,q ,jfoh3 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. Let r,f4 :j8 qoi fjho3f,vT 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 strin)gdj h2p a))iihz4mb6si j7a;9m *y4lb /dbksg forms a simple pendulum. The mass is released from rest and undergoes simple harmonic motion. Which one of th;j/2 hk4)j6di)sbmy9aimz7h* b dl )asi p4gb e 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 stopper mo.:w0ev t8flob pol./e ving at a constant speed in a horizontal circle. If the same force is applied, but the raf.l.l/0poew tb 8evo:dius 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 i1wzamypq8 sb5c(tr 56deal horizontal spring that is upstretched. A person extends the spring 1 t8s6p yqa5zm(bcw5r 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 constan m1 6hqi4ps* 8z zmv3a1.ofwdmt speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the net force acting on the mass when o.p 3zqhd is14mawm*z6 8mfv1it is at the lowest point of the circle?

  14.23:Two small identical coins (labeled X andY) are at reston ,fj0jr:r,;8n 4 bgtm an8pxjt8ml-xk 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 fro8t r,;8l-480tm:gf r,xn bjxjkmjpna 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 string and moves about torg8oe k87s u 5co4u*hhe 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 and forms an ruh*475ooe g u8ck8osangle of $θ$ with the vertical. What is the tension in the string?

  17.26: A 4.00 kg mass is in uniform circular motiow9hk4s ,rb7;7c 4ah6 wczqjafn as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of 7,c7aa wf ckh4j4hwzrq9bs;6 $θ=50^{\circ}$with the vertical. What is the speed of the mass?

  13.23: A small object of mass 11.0g is at rest 30.0 cm from a horizona kqo n)x6(gn2tal disk’s center. The disk starts to rnn(k ox6q g2)aotate from 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 = 2.0o2nr j6j2byf,p nd7* 0 cd,xpv kg is attached a distance R =1.75 m from the fixed center of a disk as shown in the figure. The nybp * ,jfc26v d2 j,0r7npoxddisk 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, wa6n - 0iffxs14imxel1;u zi8 kly (ar,ith initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwise through an angle oflkariei,0lm6 fn;y 4ixs- (f11azu 8 x$55^{\circ}$. 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 speemtp-cayh +1 1zd 17.0 m/s. The object’s speed increases un1ptz +-1hmayciformly 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. xl.x2lsu*re:q :9to) 1l uxgvThe bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motionu xx:.eglur2 v :o)l s9ql*x1t, 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.