Conor Walsh
Homework #2
1. See HW2-1.mw
2. See HW2-2(1).mph and HW2-2(2).mph
3. See HW2-3(1).mph and HW2-3(2).mph
4. See HW2-4(1).mph and HW2-4(2).mph
5. See HW2-5(1).mph and HW2-5(2).mph
6. See HW2-6.cae
7. See HW2-7.mw. Since the value of the plasticity index is greater than 1 with the initial given
information, the asperities are expected to deform plastically. In order for the asperities not to deform
plastically, they would have to have a standard deviation around 2.2 nm.
8. See HW2-8.mw. It was assumed that the surface energy was 0.07197 J/m^2 for both cases, a value
found for water in air at 25 degrees Celsius. As a result, the estimated work of adhesion was dependent
on the contact angle alone. The calculation shows that the work of adhesion of water on platinum is
much greater than that of water on paraffin.
9. See HW2-9.mph
10. See HW2-10.mw