- #1

Lukas_RSA

- 6

- 0

## Homework Statement

a Flat rectangular door in a mine is submerged from one side in water. The door dimensions are 2m high, 1m wide and the water level is 1.5m higher than the top of the door. The door has two hinges on the vertical edge, 160mm from each corner and a sliding bolt on the other side in the middle. Calculate the forces on the hinges and sliding bolt.

(Hint: consider the door from a side view and from a plan view respectively and take moments about a point each time.)

Answers: 8.327kN; 16.15kN; 24,525kN

## Homework Equations

## The Attempt at a Solution

i am able to calculate the pressure at the sliding bolt but i don't know how to approach the problem of the hinges, please help me to understand this concept.Sliding bolt:

Fsb = p(water density) g 'y A(door) / 2 'y = 2/2 + 1.5

= (1000)(9.81)(2.5)(2x1) / 2 'y = 2.5

= 24.525 kN

now i thought that to get the answer to the hinges you simply just change 'y to the desired distance, 'y = 1.5+ 0.160

and for the second hinge 'y = 1.5 + ( 2 - 0.160 )

the ansers i get is not correct, the textbook has these questions as excercises after each module.

i hope to hear from you soon.

regards

Lukas van Rooyen