It d is the depth to which a bullet of kinetic energy K can penetrate into a human body of modulus of elasticity E. Then using the method of dimension establish a relation between d, K and E. If $K=c{d}^x{E}^y$, where c is a dimensionless constant. Modulus of elasticity $=\frac{\text{ Force }}{\text{ Area }}\times \frac{l}{\mathrm{\Delta }l}$  (where l is length and $∆l$ is change in length). The value of x + y is _________