• Sir Isaac Newton was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian. He was born on 4 January 1643 at Woolsthorpe Manor in Woolsthorpe-by-Colsterworth, a hamlet in the county of Lincolnshire. At the time of Newton's birth, England had not adopted the Gregorian calendar and therefore his date of birth was recorded as Christmas Day, 25 December 1642. Newton was born three months after the death of his father, a prosperous farmer also named Isaac Newton.

Born prematurely, he was a small child; his mother Hannah Ayscough reportedly said that he could have fit inside a quart mug (≈ 1.1 litres). When Newton was three, his mother remarried and went to live with her new husband, the Reverend Barnabus Smith, leaving her son in the care of his maternal grandmother, Margery Ayscough. The young Isaac disliked his stepfather and held some enmity towards his mother for marrying him, as revealed by this entry in a list of sins committed up to the age of 19: "Threatening my father and mother Smith to burn them and the house over them." While Newton was once engaged in his late teens to a Miss Storey, he never married, being highly engrossed in his studies and work.

Every body remains in a state of constant velocity unless acted upon by an external unbalanced force. This means that in the absence of a non-zero net force, the center of mass of a body either remains at rest, or moves at a constant velocity.

Because of inertia, objects Because of inertia, objects resist changes in their resist changes in their motion. When the car going motion. When the car going 80 km/h is stopped by the 80 km/h is stopped by the brick wall, your body keeps brick wall, your body keeps moving at 80 km/h.moving at 80 km/h.

There are four main types of friction:–Sliding friction: ice skating–Rolling friction: bowling–Fluid friction: air or water resistance

–Static friction: initial friction when moving an object

The net force The net force of an object is of an object is equal to the equal to the product of its product of its mass and mass and acceleration.acceleration.

What Really Happened with the Apple?

Probably the more correct version of the story is that Newton, upon observing an apple fall from a tree, began to think along the following lines: The apple is accelerated, since its velocity changes from zero as it is hanging on the tree and moves toward the ground. Thus, By Newton's 2nd Law there must be a force that acts on the apple to cause this acceleration. Let's call this force "gravity", and the associated acceleration the "accleration due to gravity". Then imagine the apple tree is twice as high. Again, we expect the apple to be accelerated toward the ground, so this suggests that this force that we call gravity reaches to the top of the tallest apple tree.

Newton’s 2nd Law proves that different masses accelerate to the earth at the same rate, but with different forces.

•We know that objects with different masses accelerate to the ground at the same rate.

•However, because of the 2nd Law we know that they don’t hit the ground with the same force.

F = maF = ma

98 N = 10 kg x 9.8 98 N = 10 kg x 9.8 m/s/sm/s/s

F = maF = ma

9.8 N = 1 kg x 9.8 N = 1 kg x 9.8 m/s/s9.8 m/s/s

1)For every action, there is an equal and opposite reaction.2)Forces always act in pairs.

This image shows that when air rushes out of balloon, the

balloon goes up and air goes down.

When a table tennis ball comes and hits you with a lot of speed, it certainly won’t hurt you a lot.Similarly when a cricketer hits the ball at you at the same speed the ball will hurt you very much and might even cause a fracture.This is because the mass of the ball is more and thus the force with which it hits you increases according to the second law of motion.

A fish uses its fins to push water backwards. The water reacts by pushing the fish forwards, propelling the fish through the water.

As the birds As the birds push down push down the air with the air with their wings, their wings, the air the air pushes pushes their wings their wings up and up and gives them gives them lift.lift.

The baseball forces the bat to the left (an action); the bat forces the ball to the right (the reaction).