Question

calculate the work done when a student is writing exam for three hours

Answer 1

no work done becoz,

work done=distance*time

that student had not covered any distance.
work done= 0*3
. =0

Answer 2

Hello friend .
Work = force ×distance .
We don't know the force used by the student then let it be x but distance is 0.
So ,when we multiply 0 by x.
Work done according to physics will be zero .
Numerically ,
W =0×x
W= 0 .
Work done is 0 Joule .