SOLUTION: The pressure exerted by a certain liquid at a given point varies directly as the depth of the point beneath the surface of the liquid. The pressure at 80 feet is 240 pounds per sq

Algebra ->  Equations -> SOLUTION: The pressure exerted by a certain liquid at a given point varies directly as the depth of the point beneath the surface of the liquid. The pressure at 80 feet is 240 pounds per sq      Log On


   

Question 1202295: The pressure exerted by a certain liquid at a given point varies directly as the depth of the point beneath the surface of the liquid. The pressure at 80 feet is 240 pounds per square inch. What is the pressure at 30 ​feet?
Found 2 solutions by Theo, josgarithmetic:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the formula in a direct variation type problem would be y = k * x
when y = 240 pounds per square inch of pressure and x = 80 feet below the surface, solve for k to get k = 240 / 80 = 3.
that's the constant of variation.
when the depth is 30 feet, the formula becomse y = 3 * 30 = 90 pounds per square inch of pressure.
that's your solution.

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
p pressure
d depth
k variation constant

p=kd

k=p%2Fd
k=240%2F80
k=3 but be aware what the units used here are.


At 30 feet,
p=3%2A30
p=90