Classical Mechanics
# Kinetic Energy

When a ball is thrown up into the air, how does its kinetic energy change with time?

Two trucks of equal mass are moving towards each other at equal speeds.

One of the truck drivers calculates the total kinetic energy of the trucks, in her frame.

A person standing on the ground also calculates the total kinetic energy of the trucks, in his frame.

Who has calculated a greater value of kinetic energy?

If the speed of a ship doubles, then what happens to its kinetic energy?