The Young's modulus of steel is higher than that of Al (29.0 x 106 psi vs. 10.5 x 106 psi). However, for many applications such as automotive and aerospace a more important quantity is the "specific modulus," or modulus/density. Determine the specific modulus of steel and aluminium by dividing by their densities (The density of steel is about 7.86 g/cc, and the density of aluminium is about 2.70g/cc.) Note that this gives unusual units, psi/(g/cc).