95.02: An object shown in the , nu,xj 29sjva.cnl 0raccompanying figure moves in uniform circular motion. Which arrow best depicts the net force actin r.nuj,20n s,xc9valjg on the object at the instant shown?

  05.31: A child is belted into a Ferri.wll --.wmjrns Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which-llw -wrj n..m 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 ii7mj4 l)j xu gv9w8eb+n a counter4 7l)eu9ij j+ bxwvm8g- 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 velocity during this time interval?

  08.15: A particle continuously mxm/y4 s7j 5dbjkytjv.:9j v:joves 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/k.yd:5v:yvjjj j4mx7stjb 9 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 arou4)o( nlzg(p3x) uwdd mnd the vertical circle shown. Which arrow best indicates the directi4m( gwxod(z3)udp ln) on of the object’s instantaneous
acceleration at the point labeled X?

  12.11: A girl twirls a small mas.b:nrukk u9: hs connected to the 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 girl needs the mass to pass through the point labeled P in the figure, at whic:9uhkrn.k :ubh lettered point on the path should she let go of the string?

  15.23: A car moves w+-i4hx nft- *y8: utnipg5y auith constant speed around a horseshoe-shaped path as shown with the arrows in the figure. Whicp4utxh-n * fga:5tuiiyy +n-8h 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 experifnu. it2i0 / 0r/5tohs erfb8fment with a simple pendulum that is released i8o hb fsr/ifu5/ .rtn 2t0f0efrom 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 fro/ fb)wq /f2of7fpz2x k+hq0wfm 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 on the object/q7bfw k2fo)f0h 2 fz+p/xqfw?

  07.19: What net force is necessary to keep a 1. 0 kg puck moving iy c6kms+6 er/in a circle of radius 0.5 m on a horizontal frictionless surface with a specm6s6ek+y/r i ed of 2.0 m/s?

  05.03: What is the centripetal acceleratc364sd75zjs z htft*p6(tki/bf.c d z ion of an object (mass = 50 g) on the end of an 80-cm string rotating at a(c scb 7k5dz66h43 */ titpdfzjs.fzt constant rate of 4 times a second?

  09.24: A point mass moves alo5ql( js7per:o* 0 fshkng a horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnituderk7ol *50:f hqs pesj( of the net force acting on the mass as it moves?

  96.24: A 2.0-kg ball is attachu.i8f; de,pn5 5hzfh fed 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 right. The work done on the ball during each revolut 5uhni,8p.hfffd5e z ;ion is:

  99.22: A child whirls a ball at the end of a rope, inx,m:n2g76tiqko8ak w a uniform circular motion. Which of the following statem:m6wk2,tk gqoa 7xin 8ents is NOT true?

  00.19: An astronaut in an orbiting space craft attaches a mass m to a string arh:+x)e nm nf*nd whirls it around in uniform circular motion. The radi:* fe+nr )mxhnus 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 pullegq x6i( g7ob(pd outward until the string of length L to which it is attached makes a 90- degree anglqp( ibg(og6x 7e 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 terrais fi72eose h/;n, see figure to the right. Assume the car has speed v and the tops and bottoms e fis7/h;eos2 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 12.0 m/s. At t mei4n k:v qtke30or pn s.al.1/z,i6whe 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 the upward force exerted by the road on tna6.t3 vo:0 iklen 1p4qs/ rew imzk.,he car?

  97.13: A small sphere is movig;gq4tyg3fg. ng in a vertical circle at constant speed. The magnitude of the net force ot.y g4gf; g3gqn the sphere

  11.47: A simple pendulum oxw2xu1t-. l.luptvkvw9 6 q 9bf length Lhasa point mass M released from rest from the horizontal positt.9v1.u 2kxqxuwwtl6 9 lb-p vion 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 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 str 7e.26s vmysa:tfz-cwing 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 tension in the string (T), the gravitational force on the mass (W), and the net force acting on the mass (F)mywvt -ses zc67a:2 f. when the mass swings through its lowest point?

  04.41: A centripetal force of 5bc. r -os(sf8ikw*o.i.0 newtons is applied to a rubber stopper 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 w(o osi-f.si br.8*kcthe stopper?

  05.28: A mass, M, is at rest on a frictionless w0x6u)xho0 i gsurface, 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 thx0ho60 wuxi )ge necessary force applied by the person to hold the mass stationary there?

  12.22: A girl swings a 4.0 kg mass with a cona2chy2jnvt u.o h 8p048 cgy5pstant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 m. What is the 4 u2 av. h2tncjh8yoppy05cg8 net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identical lpjcoof4- *; w. )bxuocoins (labeled X andY) are at reston a horizontal disk rotating at a constaw o.-) ;* oux4bjocfplnt rate about an axis perpendicular to the 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 phct9j4jyxh5,v 4nfx-man+4 and moves about the string’s fixed end in a conical motion w5+,jhajvph4yx c9f44tx- mnn ith a constant speed of 4.0 m/s. The 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 uniform circular motion as shown in the figure. Th/;hk v t3z;1h xlzw)iiu0x/gbe string to which the mass is attached has a length of L = 3.00 m and3; ;h izxvxw1iz)b gl/hu/kt0 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 disk’ 3qvx.t f93ferqs 4v)hs center. The disk starts to rotate from rest about its center with a cofrh394q3) tfvq .xvsenstant 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 kg is attached a d8u+ bxc sggk.9istance R =1.75 m from the fixed center of a disk as shown in the figure. The dis9ggb x +uk8s.ck 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 circou 8tb9ag6f zhp7.ex1 le, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counterclockwthx bge.a1 o8u7pz 6f9ise 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 x;iu0 /l3rwhfa circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until;/ifxrw0 u3 lh 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 kta;o ul-7 m;buy/h-un4kc5bdss2s1 wm3y .d v g block rests at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope.cah;s2 sdb4mk5twu-sdy -y.o3/ vlu n; b71u m 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 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.