Sphere A has a mass of 4.2 x 10-2 kg and is tethered to a wall by a thin thread. Sphere A has an
excess of 1.2 x 1012 electrons. Sphere B has a deficit
of 3.5 x 1012 electrons and is 0.23 m from sphere A.
Determine the angle between the thread and
the wall.

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.