If you drop a bar magnet in a vertical copper pipe it will fall slowly because
A) of air resistance.
B) it induces a magnetic field in the pipe that resists motion of the magnet.
C) the copper is a good conductor of both electricity and magnetism.
D) of electron repulsion.
Answer: B
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The maximum acceleration a pilot can stand without blacking out is about 7.0 g. In an endurance test for a jet plane's pilot, what is the maximum speed he can tolerate if he is spun in a horizontal circle of diameter 85 m?
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Three forces are exerted on an object and as a result the object moves with a constant velocity. One force is 60.0 N along the +x-axis, and the second is 75.0 N along the +y-axis. What is the magnitude of the third force?
A) 135 N B) 15.0 N C) 48.0 N D) 67.5 N E) 96.0 N
A 12-g bullet moving horizontally strikes and remains in a 3.0-kg block initially at rest on the edge of a table. The block, which is initially 80 cm above the floor, strikes the floor a horizontal distance of 120 cm from its initial position. What was the initial speed of the bullet?
a. 0.68 km/s b. 0.75 km/s c. 0.81 km/s d. 0.87 km/s e. 0.41 km/s