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cord does not stretch and does not slip on the pulley.  The block has a velocity of 0.820 m/s toward the pulley when it passes through a photogate.  (a) Use energy methods to predict its speed after it has moved to a second photogate, 0.700 m away.  (b) Find the angular speed of the pulley at the same moment.  

Figure P10.43

44.A cylindrical rod 24.0 cm long with mass 1.20 kg and radius 1.50 cm has a ball of diameter 8.00 cm and mass 2.00 kg attached to one end.  The arrangement is originally vertical and stationary, with the ball at the top.  The system is free to pivot about the bottom end of the rod after being given a slight nudge.  (a) After rotates through ninety degrees, what is its rotational kinetic energy? (b) What is the angular speed of the rod and ball? (c) What is the linear speed of the ball? (d) How does this compare to the speed if the ball had fallen freely through the same distance of 28 cm?

45.An object with a weight of 50.0 N is attached to the free end of a light string wrapped around a reel of radius 0.250 m and mass 3.00 kg. The reel is a solid disk, free to rotate in a vertical plane about the horizontal axis passing through its center. The suspended object is released 6.00 m above the floor. (a) Determine the tension in the string, the acceleration of the object, and the speed with which the object hits the

floor. (b) Verify your last answer by using the principle of conservation of energy to find the speed with which the object hits the floor.

46.A 15.0-kg object and a 10.0-kg object are suspended, joined by a cord that passes over a pulley with a radius of 10.0 cm and a mass of 3.00 kg (Fig. P10.46). The cord has a negligible mass and does not slip on the pulley. The pulley rotates on its axis without friction. The objects start from rest 3.00 m apart. Treat the pulley as a uniform disk, and determine the speeds of the two objects as they pass each other.

Figure P10.46

47.This problem describes one experimental method for determining the moment of inertia of an irregularly shaped object such as the payload for a satellite. Figure P10.47 shows a counterweight of mass m suspended by a cord wound around

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