Answer
The answer is below.
Work Step by Step
We find:
a) $ W_{app} = W(1 - \frac{P_w}{P_c}) = 25(1-\frac{1}{19.3})=23.7\ N$
b) $\frac{P_c}{P_w} = (.75)(19.3) + (10.5)(.25) = 17.1$
$ W_{app} = W(1 - \frac{P_w}{P_c}) = 25(1-\frac{1}{17.1})=23.5\ N$
