95.02: An object shown in thmqva o7a* :r/oe accompanying figure moves in uniform circular motion. Which arrow best depicts the net force acting on the objectova:*/oq 7mra at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat that rotates counterclockwis2v;g k(qk) dq5tyw7.c l3ylm me at constant speed at an amusement park. At ywkl)d2 lm7; cgq vt(qm5y3.k the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously yhcf9 fq 5(i)p cfxk3*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 poin 3xf pcyh*q cf)5fk9(it P to point Q. 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 path at o l7 t7:xez,lkconstant speed in a counter- clockwise direction. Consider a time interval during which the particle moves along this circular pa,zxt7l:7e klo th 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 constant speed around the vertica),g4 ;b1yeyej dzru8ddnt+l7-n)g crl circle shown. Which arrow best indicates the direcg)j)rndt,7r+1dzbd cley-; 8egu4 ny tion of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mass con. v-c dt0etw-a0kms, vnected to the end of a string counterclockwise in a horizontal circle above her head. The figure show0vtk- s dea,ct.v-0m ws 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 a/8;.acxdfb i7ab1 jw 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 caabw c87 f1baad ji;/x.r in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a suri0r+qoad1+f e8a6rimple pendulum that is released from 1ad6 qi80+oufar+re r the 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 j1p1a:l si j-h fxu)q;i1rk3m from the 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 and turntable is 0)qrx3s lu1f 1 -hikj j;m:p1ai.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 movinf2vbmyr9xnv+m;;nz- o5c /ltg in a circle of radius 0.5 +f/v ;mnbn9z txv;l-r2 5 mcyom on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration of an object (maisg h)x ,n*ss.xjwp:,h2)k t wss = 50 g) on the end n ,thki)js 2):sx.gsww xh*,pof an 80-cm string rotating at a constant rate of 4 times a second?

  09.24: A point mass moves along a horizontal cfmp;t4i2w zu*ircular path of radius 0.8m with a constant kinetic enerui; 2* wpftzm4gy of 128J. What is 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 string and whi0 xz:b/:k 7pgzp we8cnrled in a horizontal circle at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revol/: 0gpwbcx zne8 pk7:zution is:

  99.22: A child whirls a ball at the end of a rope, in a uniform circular moz0 wbj6yo:*mz tion. Which of the followin0 zz6o*jmwy:bg statements is NOT true?

  00.19: An astronaut in an orbiting space craf o1uqtk0gf3grl 6byq5 1ut i3-6gqm; ft 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, radius, and speed were all to double the tension required to maintain mogl k10 g3 ;6fqqtuf51rtubyq63gi- uniform circular motion would be

  07.22: A mass m is pulled outward until the so64ee1cmntv01n in6j6z x qkf 51otf(tring 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 strin izem16(vc04fe6no q 511 xn 6fonktjtg 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 right uwrsz7nee,5htu6im 1/gd) * c. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver 7/d gz1wm )*nhiuuct6 s,5eer of the car is most likely to feel weightless:

  17.10: A 2000 kg car moves over a hill at. 48zcgxpmqw-b6 jbh 8 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 cxg 8 qhp-w cm.4j8zb6bhoices 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 consed . ; ffd4tz.xq97srltant speed. The magnitude of the net force on thz7lrsfedt;. xdq. f 94e sphere

  11.47: A simple pendulum of length Lhasa point mass M released from rqkiz6kc. /: 22glrhw hest 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 force acting on t ./w ik h:62k2lqcrghzhe 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 r-3n ns6.zs mvheleased from rest and undergoes simple harmonic motion. Which one of the following choices correctly ranks the magnitude of the tension ih n6mv3nzs-.s n 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*bkkqlz k*7*n rubber stopper moving at a constant speed in a horizontal circle. If the same force is applied, bubk*k kqn z*7l*t 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 fr3mq. q:1w;rpzswxwhh 1l-ml7zpn nb 7hmm(*1ictionless 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, wxl.7h3 7w1znp(h; nzrsmm l1pqw*mmq h 1:-b 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 of 3.24 m/s in a ve s6m2 . rwn+y/4mpl il:nbdo2zrtically-oriented circle of ra ml/mo:+pl dzsw6inyr.4n 22bdius 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 identicavd:aj4( adw goks(+m3l coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to the plane of the disk and thr wjdmkv aa:(o4s(+3 gdough 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 o*wz8qxaqz +8kf string and moves about the string’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a lenga+xq8zwzk*q 8 th 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 mobucu+.1)+ uzz 7ymzdvtion as shown in the figure. The string to which the masz7)z b uumyuv1c ++.zds 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 cm from a horizontal d)v otsf9;n2c misk’s center. The disk starts to rotate from rest about its center with a constant an9cs n)mfvt 2;ogular 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 kg is attached a dista1i .8ngh xxa,ince R =1.75 m from the fixed center of a disk as shown in the figure. The disk starts rotating from rea,nh i xi8g.1xst 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,yl/8 gg)ouf mo m+wst+hqh0)5hm0-bi with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moho ig0m0l)y+q+hh ug bft/s8o) m-mw5 ved 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 sps8qhs4 x;bf)eoh.mv ;eed 17.0 m/s. Thvh .ssxmo; qebh4f8); e object’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 bjhpo jey 4u4 lt)t7/0h87jrkbucket. 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 tbj/j 0j7e t78l)hry k tu4po4hhe 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.