force and law of motion

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Transcript of force and law of motion

PHYSICS PROJECT WORK

FORCE AND LAWS OF MOTION

Force is a push or pull exerted on a object

Force can change the position , size and shape of an object

There are generally two type of force balanced force and unbalanced force

Frictional force is a force which opposes motion

Force is a physical quantity

FORCE

PULL AND PUSH

A push is an applied force

acts in the direction of object

PUSH

PULLA pull is a force that acts

in the direction of

the origin of the force

NEWTONS LAWS OF

MOTION

FIRST LAW OF MOTION

Every body continues to be in the

state of rest or of uniform motion unless it is

acted upon by an external

unbalanced force

Earth is revolving around the sun

The tree is in rest

EXAMPLES -

INERTIA

The tendency of a body to remain or maintain in a State of rest or of uniform motion with respect to

The object

We tend to remain at rest with respect to the seat unti l the

Driver applies breaking force to stop the motorcar

Heavier or more massive objects off er inertia

EXAMPLE

ACTIVITY TO SHOW INTERTIA

Set a five-rupee coin on a stuff playing card covering an empty Glass tumbler standing on a table as shown in fig

Give the card a sharp horizontal flick with a finger. If we do it fast Then the card shoots

away, allowing the coin to fall vertically Into the glass tumbler due to its inertia

The inertia of the coin tries to maintain its state of rest even when

The card flows off.

MOMENTUM Momentum is define as a product of mass and

velocity

P = m v

Si unit ---- k.g.m./s

It is a vector quantity

SECOND LAW OF MOTION

The rate of change of momentum is directly proportional to the impressed force and takes place in the direction of the force

F = ma

Rate of change of momentum

P = MV ---- PROOF

Force

Change of momentumt ime

Force

F ina l momentum – in i t ia l momentum Forcet ime

Mv - mu t

f

M{v – u} t

fv – u

tA =

f ma

K is constant proport iona l i ty F = kma

K = 1F = ma

UNIT OF FORCE - NEWTON

The SI unit of force is Newton .When a body has mass of 1 kg and accerlation of 1m/s 2 then the

force said to be 1 Newton {N}

NEWTON’S THIRD LAW OF MOTION

To every motion there is a equal & opposite reaction

THANK YOU

Presented by :-

Guided by :-

Mrs. SAMTA MAM

TUSHAR SOLANKIIX “A”