Question

The speed of water in a whirlpool varies inversely with the radius. If water speed is 2.5 feet per second at a radius of 30 feet what is the speed of the watte at a radius of 3 feet?

Answer 1

Answer:

The speed of the watte at a radius of 3 feet is 25 ft per sec.

Step-by-step explanation:

Let s represents the speed of water and r represents the radius,

Since, the speed of water in a whirlpool varies inversely with the radius,

$\implies s\propto \frac{1}{r}$

$\implies s = \frac{k}{r}------(1)$

Where, k is the constant of proportionality,

Given,

When, s = 2.5 ft per sec then, r = 30 ft,

So, from equation (1),

$2.5 = \frac{k}{30}$

$\implies k = 75$

Again from equation (1),

The equation that shows the relation between r and s is,

$s = \frac{75}{r}$

If r = 3 ft,

$s=\frac{75}{3}=25\text{ ft per sec}$

Answer 2

The speed of the water in the 3 feet radius is 25 feet per second.