Newton's laws of motion help us understand why events transpire in certain ways. The three laws are F=ma and have simple yet powerful expressions: every time an object moves it will either gain speed or lose it; every time an object stops moving it will remain at rest unless acted upon by another force; and for each action there is always an equal but opposite reaction. Every day, we encounter large and small objects that are affected by forces. When we throw a ball down the hallway, ice skates across the floor, or cars collide at high speeds (even though our reactions stop them).
