Calculate fluid force on a vertical plane?

Question

need to understand the formula for calculating the force on gate 5 ft long by 4 ft wide submerged 3 ft below water the weight of water is 64.2 lb

thanks

Answer 1

You are missing info as of right now.  Did you mean to say the density of water is 64.2 lb/ft^3?

the formula will just be (Volume of water)x(Density of water) to find the force.

assuming density is 64.2 lb/ft^3 the equation will be

(3 ft)x(5 ft)x(4 ft)x (64.2 lb/ft^3) = 3852 lbf (pound-force)

The cubic feet cancel out and leave you with just pound force.

Answer 2

Pressure = density * g * height [or in this case, depth].

Force = pressure times area.

Tough in this case since force is not constant.