Newtonian Revolution Newtonian Revolution

Isaac Newton January 1643- March 1727

• Mathematician• Astronomer• Natural Philosopher• Theologian• Alchemist• Physicist

Great Works: Helped in developing differential and

integral Calculus Generalized binomial theorem Built first practical reflecting telescope Developed a theory of colors (Having to

do with the way a prism decomposes white light into many colors.)

Philosophia Naturalis Principia Mathematica (Mathematical Principals of Natural Philosophy)

Newton’s Three laws of Motion 1st Law Every object in a state of

uniform motion tends to

Remain in that state of

motion unless an

external force is applied to

it.

2nd LawA body of mass m subject to a force F, undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass. F = ma

3rd LawFor every action, there is an equal and opposite reaction.

Deeper into The First

Law

Every object in a state of uniform motion tends to

remain in that state of motion unless an external force is

applied to it.

This law means that if an object is at rest, it will stay at rest until an outside force acts on it. Likewise, when the object is in motion, it will stay in motion at a constant speed and direction until an outside force causes a

change. The image above explains Newton’s First Law in

simple terms

Deeper into the Second

Law• This law states that when a force effects

an object, the object will accelerate (change in velocity) in the direction of the force.

• The acceleration of the object is directly proportionate to the force. If the force is two times stronger, the acceleration will be two times greater.

• The acceleration is inversely proportional to the mass of the object. If you are pushing two objects with the same amount of force, and one object weighs 5 times the other, it will accelerate at 1/5 the acceleration of the other.

A body of mass m subject to a force F, undergoes an

acceleration a that has the same direction as the force

and a magnitude that is directly proportional to the

force and inversely proportional to the mass. F =

ma

F

M A

Above is a (fairly stupid) visual to help you remember Newton’s equation

To Find F- Cover F up and you will see M next to A A- Cover A up and you will see F over M M- Cover M up and you will see F over A .

Using Newton’s

Second LawSample Problem

As the result of a serve, a tennis ball (mt=58g) accelerates at 430 m/s^2 for a very brief time in contact with the racket.

A= 430 m/s^2

M= 58g (=0.058kg)

F= ma*1 Newton= 1kg x m/s²

F= (.058kg)(430m/s^2)

For this reason, the Force=24.94 N

Acceleration=

Force Mass

Photograph by The Library of Congress, 1913

Deeper into the Third Law

• In any interaction, there is a pair of forces acting on both objects.

• The size of the forces on both

objects are equal.

• The direction of the force on the second object is always opposite to the direction of the force on the first.

For every action, there is an equal and opposite reaction.

Forces come in Pears!

An Example of Newton’s

Third Law

A fish uses its fins to swim through water by pushing water backwards. However, this force is matched by the water back to the fish. The water reacting to the force of the fish, then propels the fish forward in the water. This is an example of an Action Reaction Force Pair in nature.

Action Reaction Force Pairs

Another look at Newton’s Third Law

Fa on b= -Fb on a

This equation shows how

the Force from a, on b is

equal to the negative (or

opposite) Force of b on

a

It is said that Newton’s thoughts about motion and gravity were set into action after an apple

fell on his head.

Newton knew that the apple had fallen straight to the earth because the earth attracted it. He wondered, could that gravity also be the force that attracts

the planets to the sun?

According to his third law, the apple would have to attract the earth just

like the earth attracted the apple. The force of attraction must also be

proportional to the mass of the earth

This attractive force which exists between all objects is

Gravitational Force

Newton’s Universal law of Gravitation

F= G Ma Mb

d2

•D= Distance between centers of the masses

•G= Universal Constant When Ma and Mb are measured in

kilograms, d in meters and F in newtons, then:

G= 6.67x10 Nxm /kg -11 2 2

Photographs (Sources)

Tennis: The Library of Congress

Fish: clkr.com, by: Ocal

Pears: Zazzle.ca, by: Doonidesigns

Force image: Brock Physics

Gravitational Force: astronomy.nmsu.edu/