Problem $-1(20$ points$)$

Gate $AB($below$)$ is $3$ ft wide, $4$ ft tall, hinged at point $A,$ and restrained by a block at

B$.$ Find:

$($a$)$ The resultant force from the water onto Gate $AB,$

$($b$)$ The distance of the resultant force to the top of the

water.

Note: Specific weight of water $=62\mathrm{.}4l\frac{b}{f}{t}^3.$