Example $1$:

A $500mm$ diameter pipeline is fitted with a $90$ bend.

a$)$ Calculate the resultant force on the bend if the normal operating pressure is $50m$ head of water and the discharge is $0\mathrm{.}3\frac{m^3}{s}.$

b$)$ Calculate the resultant force when there is no flow in the pipe but the system is still under pressure.