6. The diagram below shows the yield strength and density values of several classes of metallic alloys. 2000- 1000 Aluminum aloys Copper aloys Magnesium albys 500 20 Ttanium aloys 100- Brass 50- 20- 2000 5000 10000 20000 Density (kg/m^3) a. While there are many different aluminium alloys, they all have very similar densities (2700 kg/m + 10%). Similarly, all magnesium alloys have similar densities, and so do all titanium alloys. Explain why. b. Explain briefly why it is possible to engineer the yield strength of a single class of alloys so that it ranges over several orders of magnitude, even though the density of a single class of metal alloy does not vary greatly Yield strength (elastic limit) (MPa)