A hypothetical square grows at a rate of 16 m²/min. How fast are the sides of the square increasing when the sides are 15 m each?

1 Answer
Aug 30, 2016

The sides are increasing at a speed of 8/15 meters/minute.

Explanation:

The formula for area of a square is A = s^2, where s is the side length.

Differentiating A with respect to time:

(dA)/dt = 2s((ds)/dt)

Solve for (ds)/dt, since this represents the change in the sides with respect to time.

((dA)/dt)/(2s) = (ds)/dt

1/(2s) xx (dA)/dt = (ds)/dt

Here's what we know and what would be our unknown:

-We know the speed at which the area is changing (16 m^2/min)
-We want to know the speed at which the lengths of our sides are changing at the moment when the sides are 15 meters each.

1/(2 xx 15) xx 16 =(ds)/dt

1/30 xx 16 =( ds)/dt

8/15 = (ds)/dt

Hence, the length of the sides are increasing at a speed of 8/15 "m"/"min" when the sides are at length 15 meters.

Hopefully this helps!