Question

. A man holding a bucket in his hand. Give reason why no work is done by man ​

Answer 1

Answer:

He is not moving nor doing any work

Answer 2

A man is holding a bucket in his hand has done no work because there is no motion done by the man .

When there is no motion , the displacement becomes zero . Since , work is defined as the dot product of force and displacement , the work done in such case is zero .

$\tt \: w = \vec{s}. \vec{f}$

W = FscosØ

Here , s = 0

Hence , W = 0 .

More about work :

•It is a scalar quantity as it is a dot product of two vectors .

•It SI unit is Joule .

• Work is zero when :

1) Force is zero

2) Displacement is zero

3) Angle between force and Displacement is 90° .

• When angle becomes 90° , cos 90° = 0 , hence no work is done .