# Newton's Law of Motion

## Newton's 1st Law

• An object moving at a constant velocity keeps moving at that velocity unless a net force acts on it. (An object at rest stays at rest unless a net force acts on it)
• An object in motion continues to move in the same direction at the same speed until a force changes its direction.
• An object in motion will stay in motion until acted by an outside force
• Example: A soccer ball will not move until it is kicked

## Newton's 2nd Law

• Acceleration of an object is in the same direction that the net force is applied on the object

• Force = mass x acceleration

• The greater the force, the greater the acceleration

• The mass of an object and the force applied to it affect acceleration

• Acceleration of an object is in the same direction as the net force on the object, and that the acceleration equals the net force divided by the mass

• Example: You have to push a heavy ball harder to get it to move as fast as a small ball

## Newton's 3rd Law

• When an object exerts a force on a second object, the second object exerts a force on the first object that is equal in strength and in the opposite direction
• For every action there is an equal and opposite reaction
• The greater the mass, greater the momentum

• Action-reaction forces act on different objects and differ from balanced forces

• Example: A fireman turns on his hose and is knocked backwards

## Videos About the Laws of Motion

Newton's Law Of Inertia
Newton's Second Law of Motion
Newton's 3rd Law of Motion