Energy, E∝AaTbPc Or, E=kAaTbPc ....(i) where k is a dimensionless constant and a, b and c are the exponents. Dimension of momentum, P=M1L1T−1 Dimension of area, A=L2 Dimension of time, T=T1 Putting these value in equation (i), we get M1L2T−2=McL2a+cTb−c by comparison c=1 2a+c=2 b−c=−2 c=1,a=