$1.$ Using the constants and conversion factors defined for mass, length, time, and temperature, calculate the conversion factors for:

$($a$)$ force in foot$-$pounds to kilowatthora

b$)$ gallons $(1$ gal $=231$ in$\mathrm{.}3)$ to liters $(103$ cm$3)$

c$)$ Btu per pound mole to joules per kilogram mole.

Please make it as detailed and explanatory as possible because I want to study and$$understand$$it$.$