Assume a person weighs 90kg, and that this weight causes the bones in her legs to contract when she is standing upright. If we model the bones in the legs to be cylinders 1.6cm in diameter and 87cm in length, estimate the increase in the length of a person when they lie down as compared to their length when they stand up. Assume that Young's modulus of bone in compression is 9 x 10⁹ N/m² and in tension is 16 x 10⁹ N/m². (we have 2 legs)