Make all capitalization consistent with the rules of convention outlined in the American Heritage Dictionary. DO capitalize: The first word and any proper nouns in a title, heading, or subheading. Proper nouns, months, days of the week, but not the seasons.
Newton (unit) The newton (symbol: N) is the SI unit of force. It is named after Sir Isaac Newton because of his work on classical mechanics. A newton is how much force is required to make a mass of one kilogram go faster at a rate of one metre per second squared.
Newton's laws of motion. Newton's laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces.