Question

Coolie walking with load on his head does no work against gravity

Answer 1

yes that's true that coolie carrying a load on his head does not do any work against gravity because the displacement of collie with the load on his head is at right angles to the gravitation force.

w= f× S costhita

w= 10m/s2( force of gravity) × 0(here costhita is equal to 90 degrees and we know that cos ninety degrees is equal to 0)

w= 10× 0

= 0

we must not here that work is not done against gravity but work is being done by the coolie against the force of friction.

Hope that helps!

Answer 2

$\huge\star\mathfrak\red{{Hey Mate...!!}}$

● The work done will be zero because a coolie carries a load make an angle of 90 degree wherever the 90 degree created the work done will be zero.

Proof:

W = FS Cos Q

W = FS Cos (90°)

W = FS (0)

W = 0