Problem 1.7 Estimate the specific gravities (gas) for methane and propane. Their molecular weights are shown in Appendix E. (Commercial natural gas and commercial propane are mostly methane and propane, with small amount of other substances, which may be ignored for this problem.) Which is more dangerous, a natural gas leak or a propane leak? Why? Problem 1.8 What are the dimensions of dV/dy? What are the dimensions of shear stress? Shear stress in liquids is often called the "momentum flux." Show that shear stress has the same dimensions as momentum/(area. time). What are the dimensions of viscosity? Problem 1.7 Estimate the specific gravities (gas) for methane and propane. Their molecular weights are shown in Appendix E. (Commercial natural gas and commercial propane are mostly methane and propane, with small amount of other substances, which may be ignored for this problem.) Which is more dangerous, a natural gas leak or a propane leak? Why? Problem 1.8 What are the dimensions of dV/dy? What are the dimensions of shear stress? Shear stress in liquids is often called the "momentum flux." Show that shear stress has the same dimensions as momentum/(area. time). What are the dimensions of viscosity