A book that weighs 20 N sits on a table. How big and in what direction does the force of gravity from the Earth act on the book? A. 20 N down
B. 10 N down
C. 20 N up
D. 10 N up

What is the most useful equation for electric power?

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

Two manned satellites approaching one another at a relative speed of 0.550 m/s intend to dock. the first has a mass of 2.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. assume that the positive direction is directed from the second satellite towards the first satellite. (a) calculate the final velocity after docking, in the frame of reference in which the first satellite was originally at rest.(b) what is the loss of kinetic energy in this inelastic collision? (c) repeat both parts, in the frame of reference in which the second satellite was originally at rest. final velocity(d) loss of kinetic energy = ?