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NEWTON’S SECOND LAW OF MOTION

Difference: First and Secon laws

First law explains the motion of the body when there is no external force

Second law of motion handles the situation where there is a net external force.

It relates the net external force to the of the body

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Momentum

The product of mass and velocity is the momentum. Which is evidently a relevant variable of motion

Momentum is the effect of force on

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Impulsive Force

For a same change of momentum on a body, shorter time needs a greater applied force.

force acting on a S interval time is the Impulsive force

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Definition: Second law of motion

The rate of change of of a body is directly proportional to the applied force and takes place in the direction in which the acts

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One Newton

F = ma

If m = 1 kg, a = 1 m/s2, then F = 1 newton

One newton produces unit on a body of unit

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Impulse

An experienced Cricketer takes possible maximum time for the process of catching the ball to reduce force

Question 1

Impulse = Force × time duration = Change in momentum

Hint

Force not only depends on the change in momentum, but also on how fast the change is brought about

Some points of Second Law

If external force is zero, acceleration is zero. It is obviously

The second law of motion is a vector law. The component of velocity to the force remains unchanged

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Historical and Internal Forces

We know the relation, F = ma is a local relation

a is the acceleration of the system as a whole

And F is the total external force on the system

forces in the system are not to be included in F

here and now is not determined by any historical forces acted on the body

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