Answer:
Area is 0.08504
and
are needed for polishing
Explanation:
(a) ft is unit of F.P.S system whether mm is unit of M.K.S system.
According to unit conversion, 
So, 
hence, 
So, area of telescope lens is 0.08504
(b)
are polished in 45s
So,
are polished in
or 
The formula to convert from Celsius to Fahrenheit is F = 9/5C + 32 or F = (C*1,8)+32
F = 9/5*39 + 32 = 70,2 + 32 = 102,2° F
1 mole = 6.022*10^23 atoms
4.2 moles sulfur = 4.2* 6.022 * 10^23 sulfur atoms = 2.421*10^24 sulfur atoms
1 mole sulfur = <span>32.065 g sulfur
4.2 moles sulfur = 4.2 * </span>32.065 g sulfur = 128.901 g sulfur