\(v = \frac{{100}}{{10}} = 10\,m/s\,\,\,\,\,\,\therefore \,K.E. = \frac{1}{2}m{v^2}\)
If mass is \(40\) \(kg\) then, \(K.E = \frac{1}{2} \times 40 \times {\left( {10} \right)^2} = 2000\,J\)
If mass is \(100\) \(kg\) then \(K.E = \frac{1}{2} \times 100 \times {\left( {10} \right)^2}\) = 5000 J