Question

the speed of water in a whirl pool varies inversely with the radius. if the water speed is 2.5 feet per second at a radius of 30 feet what is the speed of the water at a radius of 3 feet

Answer 1

Explanation:

Let, the Speed of the water be 'x'

and the Radius be 'r'

Now, the speed of Water Varies inversely with the Radius

So, x ∝ 1/r

x = k/r -----------(i)

Here, k is the proportionality constant

Now,

Given that, x = 2.5 ft per sec

then, 30 ft,

So, from eq. (i)

2.5 = k/30

So, k = 75

Again From eq. (i)

x = 75/r

Now, if r = 3ft

then, x = 75/3

x = 25

Hence, Speed of the water (x) = 25 ft per sec.