Two blocks of masses 'M' and 'm' are placed on one another on a smooth horizontal surface as shown in the figure. The force 'F' is acting on the mass 'M' horizontally during time interval 't'. Assumings no relative sliding between the blocks, The work done by friction on the blocks is

Options

A. `(m F^2 t^2)/(2 (M + m)^(2))`
B. `(F^2 t^2)/((M + m))`
C. `(M + m)/(m^(2))`
D. `(Ft)/(2(M + m))`

Answer

A