What is the work done by a coolie walking on a horizontal platform with a load on his head?

At what speed will a body of mass $1\, kg$ have a kinetic energy of $1\, J$ (in $, m/s$)?

$(a)$ Define work done by a constant force on an object. Write an expression for the work done.
$(b)$ How much work will be done on an object by a force if the displacement of the object is zero?
$(c)$ What is the kinetic energy of an object? Write an expression for the kinetic energy of an object of mass $m$ moving with a speed $v$.

List two conditions which need to be satisfied for the work to be done on an object.

Calculate the electricity bill amount for the month of April if $4$ bulbs of $40 \, W$ for $5 \, hrs$, $4$ tube lights of $60 \, W$ for $5 \, hrs$, a $TV$ of $100 \, W$ for $6 \, hrs$, and a washing machine of $400 \, W$ for $3 \, hrs$ are used per day. The cost per unit is ₹ $1.80$.

$A$ boy pushes the wall in the class for five minutes but the wall does not move. Another boy pushes the chair from the front to the back side of the class. In which case,more work is done?