Question

Air flows at 45m/s through a right angle pipe bend with a constant diameter of 2cm. What is the overall force required to keep the pipe bend in place? Is it: a) 0.76 N b) 1.08 N c) 1.52 N d) 0.25 N e) 2.56 N

Answer 1

Answer:

b)1.08 N

Explanation:

Given that

velocity of air V= 45 m/s

Diameter of pipe = 2 cm

Force exerted by fluid  F

$F=\rho AV^2$

So force exerted in x-direction

$F_x=\rho AV^2$

$F_x=1.2\times \dfrac{\pi}{4}\times 0.02^2\times 45^2$

F=0.763 N

So force exerted in y-direction

$F_y=\rho AV^2$

$F_y=1.2\times \dfrac{\pi}{4}\times 0.02^2\times 45^2$

F=0.763 N

So the resultant force R

$R=\sqrt{F_x^2+F_y^2}$

$R=\sqrt{0.763^2+0.763^2}$

R=1.079

So the force required to hold the pipe is 1.08 N.