95.02: An object shown in the accompanying figure moves in uniforn.j vz24p ni3tm circular motion. Which arrow best depicts tht.pn zj4v2n3 ie net force acting on the object at the instant shown?

  05.31: A child is belted into 6,ks0ow8gy 0vflo i*fa Ferris Wheel seat that rotates counterclockwise at constant speed at an amusement park. At the location shown, which direction best represents the total force exerted on k8f0oil 6wf0 gvyo*s, the child by the seat and belt?

  08.14: A particle continuously moves in a cirelu5)16e p.mzu vcf(5v.kc zycular path at constant speed in a counter- clockwise direction. Consider a time interval during which v5czfel 6(ycp.51zm .kevu)uthe 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 moves in arb c3svdc;0y+ sg:2 ih 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- gc crs;0i 3bhsvd+:2yway 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 +udl/on*tpkp3v( n4-e bnq5 maround the vertical circle shown. W+ dlb nt4(ump -/*voqnpek 53nhich 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 coo/w zo+/ osh h8nk.t jbza;s9,unterclockwise 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 which lettered point on the path should she let o jw9/ob; h/,sz+z.noa khst8go of the string?

  15.23: A car moves with constant speeud/db4gf67xmz7a/a 5;sd hka d 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 acceleraxa7uhg6b7sdd 5/;/ka4 maz fdtion of the car in traveling from Wto X?

  08.35: Astronauts on the Moon perform an experiment with a simple pendu t-t tz1k06kzalum that is released from the horizonta-1ztk0ktz6 atl 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 o0vpt9 esf ,ke2/ k*urkbject rests 2.0m from the center of a rough turntable as the turnt,9te 2k0pvk/r kefu*sable 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 /s4rx* ucup2w qb)v)va 1. 0 kg puck moving in a circle of radius 0.5 m o4wqbxus vp 2))* uv/rcn a horizontal frictionless surface with a speed of 2.0 m/s?

  05.03: What is the centripetal acceleration o2 h 3 (,yi:mejjx,v f4b1nik*qefvq;ff an object (mass = 50 g) on the end of an 80-cm string rotating at a constant rate of 4 times3f beqj(hyk; 41:i2x m j,f*qvefn,iv a second?

  09.24: A point mass moves along aal/e b (ac;*shc4tt3y horizontal circular path of radius 0.8m with a constant kinetic energy of 128J. What is the magnitude of t4*tch ba3a st /(y;clehe 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 whirled i1wpq8puu/1xwhl6 akg,0x+cb n a horizontal circl11wk8 c+ u6u, xwg0abh qpp/lxe at a constant speed of 6.0 m/s. See figure to the right. The work done on the ball during each revolution is:

  99.22: A child whirl ch- fiea)-3mqhwpxdl)t z1: +s a ball at the end of a rope, in a uniform circular motion. Which of the follow efmwli -:- 3p1h+qxatzhc))ding statements is NOT true?

  00.19: An astronaut in an orbitic/ej3( v x;kvexf *0zeng space craft attaches a mass m to a string and whirec*( ezxv0v fj;3ke/x ls 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 uniform circular motion would be

  07.22: A mass m is pulled outward until tzk1o8 kbi(u hx +km0t.kp:4iyhe 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 bottokp o:i. b1k04 ( hkk8umx+tiyzm ofthe arc?

  94.15: A car is traveling oe(xxqgld9k / 1j) nv(zn a road in hilly terrain, see figure to the right. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of the(1 k jlxzdx9 )g(enq/v car is most likely to feel weightless:

  17.10: A 2000 kg car mo(lmmi; rb1wy +ves 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 wm b ;yr+i(1mlbest 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 consta*t q49lefb(h,xsuekc5;+ t y4ik) k wpnt speed. The magnitude of the ne(lu4+s ,t*f9)ihckpykt ex5 q4b; kwet force on the sphere

  11.47: A simple pendulum of leu f+) 6a+:hlr xmkl3cii0oyl,ngth Lhasa 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 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 b: ifcx ,huk6o )mly+3al0 irl+y 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 pexk :fvlujwja5rvy;2txg h.o62kl50w b- 7r7 dndulum. The mass is released fromvly6 l7 xk v 20;whgr.t7dwujj: -baokf52rx5 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) when the mass swings through its lowest point?

  04.41: A centripetal force of 5.0 newtons is applied to a ru/a/rx wu(n-w jbber 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 freque x-/nrajuw/( wncy f, of the stopper?

  05.28: A mass, M, is at rest on a frictionless o358/ *i uxaejevajc5 surface, connected to an ideal horizontal spring that is upstretched. A person extends the spring 30 cm from equilibrium and he*3acjuxijva85 e 5 /oolds 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 masszuj::emx6ktj5 q 3 jd9 with a constant speed of 3.24 m/s in a vertically-oriented circle of radius 0.75 mquxke9::d 6jj 5t z3jm. What is the net force acting on the mass when it is at the lowest point of the circle?

  14.23:Two small identicaln7m 7s s8kt5f 2 ua0kq5denm8c coins (labeled X andY) are at reston a horizontal disk rotating at a constant rate about 5q8mn0c8eau2kk75sf dmnt7 san 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 con6r za sj80n2uqnected to the end of 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 length6z 2r0suqn8aj 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 u5xwa 003czt1d5v rfckniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 5x30ca1vrw dz5fktc0m 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.unjqc-1 m8/uz 0g is at rest 30.0 cm from a horizontal disk’s center. The disk starts to rotate from rest abouzq-u/cm18j un t 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 Mdxjxyig l*xye.05v; 6 = 2.0 kg is attached a distance R =1.75 m from the fixed center of alyx5.*yv ide0 6j xgx; disk as shown in the figure. The disk 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, stau. 2jp aiju6 4a,) *qxvl2swaorting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly until it has moved counter *j)u,2 q4a.il6pjs uoa2 awxvclockwise 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 i5-co bh)2 fe8tbnhh;z i1cs 2nn a circle, starting at the top, with initial speed 17.0 m/s. The object’s speed increases uniformly un nb2;1cn e)chf2z8s5tib ohh-til 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 ak 6k29i1ghn p iv*uwk5t the bottom of a bucket. The bucket is spun in a vertical circle of radiuipkwhuinkgv165* 9k 2s 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 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.