Question

A worker does 196 J of work to lift a bag 2m. What is the mass of the bag?

Answer 1

Work = 196 J = 196 kg.m^2.s^-2

[We know that 1J = 1 kg.m^2.s^-2]

Displacement = 2m

Acceleration (g) = 9.8ms^-2

We know that,

W=Fs and F=ma

So, W = (ma)s

=> W = m×a×s

=> 196 kg.m^2.s^-2 = m×9.8ms^-2×2m

=> 196 kg.m^2.s^-2 = m×19.6m^2.s^-2

=> 196 kg.m^2.s^-2 = m×19.6m^2.s^-2

=> (196 kg.m^2.s^-2)/(19.6m^2.s^-2) = m

=> 10kg = m

So, mass = 10kg