In the late 1600s, the English scientist Isaac Newton came up with three laws that deal with forces and motion.
The first law says that the motion of an object will not change unless a force pushes or pulls it.
The second law says that a force on an object will make the object speed up in the same direction as the force. Also, a strong force will make the object speed up faster than a weak force on the same object.
The third law says that whenever a force pushes on an object, the object pushes back with an equal and opposite force.