Laws of Motion

• Isaac Newton's laws

1. Every object will stay in a state of rest or motion unless an outside force acts on it
   • The motion will have a constant speed
   • Restatement of Galileo's discovery of the conservation of momentum
   • Sometimes called the law of inertia
2. Change of motion of a body is proportional to and in the direction of the force acting on it
   • $\Sigma\vec{F} = m\vec{a}$
   • If you want to accelerate anything, you have to apply a force
     • A net force causes acceleration
3. For every action there is an equal and opposite reaction
   • Mutual actions of two bodies upon each other are always equal and act in opposite directions
   • The "action" force and the "reaction" force are acting on different objects
   • $\vec{F}{AB} = -\vec{F}{BA}$

Physics