Newton’s Laws of motion

Who Exactly Was Isaac Newton?

Isaac Newton was an English physicist, mathematician, astronomer, philosopher, and to many, the greatest and the most influential scientist who ever lived.

Isaac Newton was born in Lincolnshire, England on December 25, 1642. He was born premature and his father had died of a sudden illness three months before he was born. His mother, Hannah did not expect Isaac to live through the night but he did. She remarried when Isaac was three years old. She left Isaac with his grandparents and saw very little of him for the next eight years.When his stepfather died, Hannah returned to the farm.She was financially secure andplanned for Isaac’s educationas a gentleman farmer.

Isaac did not like school and had very few friends. He was very small and picked on by bullies. On one occasion, he was tired of being picked on and beat up a boy a lot bigger than him. After that, the bullies left him alone. There seemed to be a steely toughness that ran through him. He roomed with Mr. Clark, who ran an apothecary. He showed Isaac how to mix potions and supplied him with many books to study. His favorite book was The Mystery of Nature and Art by John Bates.

He soon excelled in school and rose to the top of his class. At 17, Hannah called him back home to run the farm. Henry Stokes plead with Hannah to let him continue his studies and she finally agreed. He had no financial support from his mother and he had to find a way to work his way through college. He waited on tables and cleaned the wealthier students rooms. He became especially interested in Math and learned everything about it at this time.In 1665, he received his BA. The plague began spreading through Europe and school closed. Newton returned home for 18 months. It was then that he sat under the trees on the farm studying his

He watched an apple fall from a tree and thought that this force of gravity must be the same force that holds the Earth and planets in orbit. He did not know exactly what gravity was but he described how it worked. He also studied light and color. Using a prism, he discovered that white light was all colors.

Isaac Newton built the first reflecting telescope using mirrors. He also invented Calculus which is the math of changing motions.Newton had a nervous breakdown in 1693 after his only friend, Fateo moved. He recovered quickly but was never the same. He became Master of the Mint and in 1705, Queen Ann knighted him. Isaac Newton died March 20, 1727. He was buried in Westminster Abbey.

The single most important scientific book was written by Newton in 1687– The Principia

This book described the orbit of the planets, inertia and his laws of motion.

1st Law of Motion

• Inertia- the tendency of objects to remain in motion or stay at rest.

• This concept of inertia forms the basis for Newton’s First Law of Motion.

• The first law of motion states that an object at rest will remain at rest and an object in motion will remain in motion at constant velocity unless acted upon by an unbalanced force.

Examples: Riding in a car and it stops suddenly, you keep moving forward. Your seatbelt keeps you from sending you through the windshield.

Standing on a bus– when the bus starts to move forward, you are thrown off balance and fall backward. When the bus stops, you fall forward.

A car traveling along a road will tend to move in a straight line. When the road curves, the driver turns the steering wheel and the people in the car continue to move in a straight line and bump into the walls of the car.

Acceleration and force are related: Acceleration cannot occur without a force.

2nd Law of Motion• Newton’s second law of motion shows how

force, mass, and acceleration are related.• Force = Mass X Acceleration• If you push on a grocery cart, it begins to move.

The harder you push, the faster the cart accelerates. The greater the force, the more the acceleration. If the cart is filled with groceries, you have to push harder because the groceries have more mass. Force and acceleration must be related to an object’s mass.

Examples: Small car gets better gas mileage than a large car.

Basketball is harder to throw than a baseball.

A full grocery cart is harder topush than an empty cart. Itrequires more force.

3rd law of motion• Newton’s third law of motion states that for

every action, there is an equal and opposite reaction.

• Push down on the edge of your desk with your hand. The desk may not move, but your hand will have a mark on it. This mark is evidence that a force is being exerted on your hand. The desk is exerting a force. The harder you push on the desk, the harder the desk pushes back on your hand.

Examples: Walking– as your feet push against the floor, the floor is pushing against your feet.

A bird flying– the bird exerts a force on the air, the air pushing back on the bird’s wings propels the bird forward.

A rocket blasting off– fuel produces hot gases which push against the inside tube of the rocket. This escapes out the bottom of the tube and causes the rocket to move in the opposite direction….upward.

Conclusion

• Newton’s three laws of motion can explain all aspects of an object’s motion. His first law explains that forces are necessary to change the motion of an object. His second law describes how forces and acceleration are related to mass. His third law explains that forces act in pairs.