Determine the actuation force required to open the door under the nominated differential head of $2\mathrm{.}4$m measured from the bottom of the sill plate.$($this is also bottom of the gate$).$ THe gate opens along the y axis

assume the friction coefficient between the frame and the seal is $0\mathrm{.}7$ and the penstock door's mass is $81\mathrm{.}95$ kg

Note gate doesn't sit within the body of the water. Rather it is part of the penstock used to contorl water flow.

the length of the gate is $1010$mm and width is $980$mm$.$

Please explain in detail what forces will act in a FBD$.$