Newton’s First Law of Motion Newton’s Second Law of Motion Objects at rest remain at rest. Objects in motion remain in motion in a straight line unless acted upon. Force equals mass times acceleration F=m×a Newton’s Third Law of Motion For every action there is an equal and opposite reaction. The amount of matter contained in an object, such as the amount of air contained in a balloon or the amount of water in a glass. MASS Unless altered, this remains the same whether the object is on Earth, in Earth orbit, or on the Moon. It represents the force of gravity acting on a mass. WEIGHT This quantity will change depending on the force of gravity acting on the object. F = m ×g Force multiplied by the amount of time it acts over. IMPULSE Also, the change in momentum. ACCELERATION A change in either the speed or direction of motion. For example, when you step on the accelerator pedal of a car, you cause in increase in this. A Push or a pull exerted on an object. Examples include muscle power, movement of air, and electromagnetism. FORCE When an object is at rest, this is balanced. When an object is in motion, this is unbalanced. All matter, because of its mass, resists changes in motion. INERTIA The more mass, the more resistance. MOMENTUM The quantity of motion affecting an object. Mass times velocity. Other possible ideas: Gravity - The force of attraction between masses. Gravity is the force that makes objects fall to the ground. Speed – Velocity -