Question

Can you tell? 1. In which of the pictures above has work been done? 2. From scientific point of view, when do we say that no work was done?​

Answer 1

Answer:

where are the pictures? ..........

Answer 2

The work has been done in -

(2) A boy playing foot ball

A boy playing foot ball (4) A labour lifting a gunny bag of seed.

We say no work is done in following conditions

• We need to tell when no work is done in the give conditions from scientific point of view.
• We know that, Work is represented by the formula -

$W = F.d \cos(θ)$

Where,

W = Work done

F = Magnitude of force applied

d = displacement

θ = angle between the displacement vector and force.

• When no work is done, either magnitude of force or displacement is zero.
• In the given picture (i) and picture (ii) The girls are sitting and studying and watch television respectively, No external force is acting on another object and no displacement has occurred.
• Therefore, no work is done in the given situation.

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