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When a hard rubber rod is given a negative charge by rubbing it with wool:

How much work is required to stop an electron  ( m = 9.11 x 10 – 31 kg) (  which is moving with a speed of 1.90 x 10 6 m/s?  

An acorn falls from a tree.  Compare its kinetic energy K, to its potential energy U.

An electrical insulator is a material:

On a balanced see saw, a boy three times as heavy as his partner sits   A)   1/3 the distance from the fulcrum.   B)   less than 1/3 the distance from the fulcrum.   C)   more than 1/3 the distance from the fulcrum.    

A rifle of mass 2 kg is suspended by strings. The rifle fires a bullet of mass 0.01 kg at a speed of 200 m/s. The recoil velocity of the rifle is about

Only if a force on a particle is conservative:

True or False: The acceleration of gravity experienced by objects located near to (and far from) from the earth depends upon the mass of the Earth.

A 50-kg platform diver hits the water below with a kinetic energy of 5000 Joules. The height (relative to the water) from which the diver dove was approximately ____ meters.

Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a tower, they reach the ground at the same time, but the heavier one has a greater A)