95.02: An object shown in the accom2r :utlx n16ijh,d7( li3xv cspanying figure moves in uniform circular motion. Which arrow best depicts the net force actvhr (1tl,ujlcd 3i:xx27ins6ing on the object at the instant shown?

  05.31: A child is belted into a Ferris Wheel seat n2lcg 5)dgqp+ that rotates counterclockwise at constant speed at an amusementngqd )p+52gcl park. At the location shown, which direction best represents the total force exerted on the child by the seat and belt?

  08.14: A particle continuously moves in a circular path at constant speed in w f8lz3w( ul2ca 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 exactfw zlcl3w( 8u2ly 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 constant zey (7xurb*r7 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 exaxrb zr7e*(uy7ctly half-way around the circle from Point P.
What is the direction of the average acceleration during this time interval?

  15.07: An object movekr*s,p6pc ka8)5daq7ry,s 0pfgikb:s clockwise with constant speed around the vertical circle shown. Which arrow best indicates the 7apk r*):gi 68k5s rc 0,sppdbfqay,kdirection 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 counterclockw+vz kg,j;7yiyc3lr. txz:sk . ise 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 thr. g;yx+rsv7z3ck ji:y .k zl,tough 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 hors+5w;2sms4 h roai9vhjeshoe-shaped path as shown with the smhvoaj2s ;w 4i59+rh 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 pahnt(i -r, pt,erform an experiment with a simple pendulum that is released from -rh ,pna(,titthe 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 rnge)-:zg fa+ f y0gx0pests 2.0m 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 0.50, while the coefficient of static friction is 0.80. What is the magnitude of the force of friction acting o-)f gygex 0pn0+ agzf:n the object?

  07.19: What net force is neces2pinh a;fj ptde** 10zv-dh;d sary to keep a 1. 0 kg puck moving in a circle of radius 0.paphd;dv*;-j 02fn1 i z*etd h5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the cenp9xjvawh;9: vr4nx + jtripetal acceleration of an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times9n9v;xv jp4 hr+jxw: a a second?

  09.24: A point mass moves along a horizontal circular path of ra-lg -e-m9uyu,zm6iotr+jg f 1 dius 0.8m with a constant kinetic energy of 128J. What is the magnitude of the net force acting on th-,1 r- zg- uj6iot9f e+mlgmuye mass as it moves?

  96.24: A 2.0-kg ball is attached to a 0.80 m string and wv )28 pdfz+,fiy x8etmodj6) lhirled 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 revolution m8)lx8d,dtyp2e ffz +) ovij6is:

  99.22: A child whirls a ball at thcbwqn3wwj3+1 q s ozz5i/e 85ee end of a rope, in a uniform circular motion. Which of the following statements o5zwwsi5n 8/13 qqce+jbz e3 wis NOT true?

  00.19: An astronaut in a13m 6 -lc corm/iupn ks9t/*hmn orbiting space craft attaches a mass m to a string and whirls it around in uniform circular motion. The radius of tr ucmtl9/* o3c-mm/ps6hink1he 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 whmq* gyqp r)84 lxpck t)ome5*5ich it is attached makes a 90- degree angle with the vertical. The mass is rex m)rtk)8*loep 5ygcqqm5*p 4leased 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 rfp5 (.eh64i q(xpdnz7acc3bqoad in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottom43e aqz(i7c n(cd56.qxb ppfhs 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 gbm3f*up q*y* 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 magn3qmpby u **gf*itude 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. The magncxa3tif zuia ii ,;q)1 ch io-d;+0ul+itude 30ul+)i;aq;c t -ixd ci+a1,oufiizh of the net force on the sphere

  11.47: A simple pendulum of length Lhasa point mass M rel4m p0mcqxw a72eased 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 represent the magnitude of the force from theqw2 mm7a0c4p x 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 6x+ p:dmywj 0b781ndwsjf i ja8u/ )rnto a string forms a simple pendulum. The mass is released from rest and undergoes simple harmo yajdnf/0:)sjp 8rjmb8+1u6 winxdw 7 nic 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 formw)bx9strm.7: u1cn psoue5j35ls0hbh9s. z ce of 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same force is appliechp7l0t sbxs h)r3.9:5ns 5u e .1bzo9ju mwsmd, 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 ideal hf-y, 4dr)rll-rxda b* orizontal 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 xd y4f )d rlrr*-ab,l-hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a constant speef c4hvr;nm99m d 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 it is at the lhvmr n;4f 99mcowest point of the circle?

  14.23:Two small identical coiozp.ai -ni+3z ns (labeled X andY) are at reston a horizontal disk rotating at a constant rate about an axis perpendicular to theo.p-3a z+niiz plane of 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 stvn+n 9 qto7n(;l , aws7dexyq8ring’s fixed end in a conical motion with a constant speed of 4.0 m/s. The string has a length of 2.xn y,wq d8+7 le;ovn 7a(tsqn950 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 mo)s d2 9dqjxh(qi/q t7xtion as shown in the figure. The string to whjhqtq9q7s)d /(2x xdiich 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 30.0 cm from a horizontal diskc)zf5x n9e8w s yo-8eh’s center.nh5fsco)e 9wyx-ez88 The disk starts to rotate 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 cms9p/s6ud, isn t *7g*dp 9cbmass M = 2.0 kg 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 with constant angular acce,bsdu gc*m/pipt979 s6ns* cdleration $α =5.00 rad/s^{2}$ 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 to0g mi xeju*5k+p, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved count5kgum *xj+0ei erclockwise 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, start gsi,l1h+-hl;(yl+ ykw 3t nmmi9a+f ning at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterii3g,nms 1aklll;hymn(+f +9tyh-+ wclockwise 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. T0g3e puh2; 4dt rpc3 niqjgon2j9z..ahe 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 the bucket. When the bc 3q4;p a nniz0og3.g j9ut.rhpj 2de2ucket 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.