Answer: n=4
Explanation:
We have the following expression for the volume flow rate of a hypodermic needle:
(1)
Where the dimensions of each one is:
Volume flow rate
Radius of the needle
Length of the needle
Pressures at opposite ends of the needle and
Viscosity of the liquid
We need to find the value of whicha has no dimensions, and in order to do this, we have to rewritte (1) with its dimensions:
(2)
We need the right side of the equation to be equal to the left side of the equation (in dimensions):
(3)
(4)
As we can see must be 4 if we want the exponent to be 3:
(5)
Finally:
(6)
