Question

A triangular plate with base 2 m and height 3 m is submerged vertically in water so that the tip is even with the surface. Express the hydrostatic force against one side of the plate as an integral and evaluate it. (Round your answer to the nearest whole number. Use 9.8 m/s2 for the acceleration due to gravity. Recall that the weight density of water is 1000 kg/m3.)

Answer 1

Hydrostatic Force = 35.28KN

Explanation:

To solve this question, let's consider integrating the hydrostatic force from the top of the triangle to the bottom.

Formula for a thin horizontal slice of the triangle the force is;

δF=ρgxwδx

Where w is width of triangle; ρ is density of water and g is acceleration due to gravity

At depth x, the width of the triangle is w=2/3x.

Thus, F = (3,0)∫)ρgxwδx

=(2/3)ρg[(3,0)∫)x²δx]

= integrating, we have;

F = (2/3)ρg[(3³/3) - (0³/3)]

F = (2/5)ρg [27/3] = (2/5)(1000)(9.8)(9) = 35280 N = 35.28 KN