What happens to water when it changes to ice?
it's density increases.
it's density decreases.
it's mass increases.
it's mass decreases.
it's volume increases.
it's volume decreases.

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

The slope of a velocity time graph over any interval of time gives the during that interval

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?