Question

A marble dropped in still water will create circular ripples or waves. The radius of each circular wave will increase 4

centimeters per second. What is the circumference of the circle after t seconds?

Answer 1

C: C(t) = 8πt

Explanation:

Answer 2

Circumference of the circle after t seconds =
`8\pi t` = 25.12t

Explanation:

Given

radius of each circular wave will increase 4

centimeters per second

In 1 second radius of circular wave = 4cm

in 1*t second radius of circular wave = 4*t cm

Thus, radius of circular wave after t second will be 4*t cm

We know that circumference of circle is given by =
`2\pi r`

where r is the radius of the circle

Thus, radius of circular wave after t second will be =
`2\pi`* radius of circular wave after t second =
`2\pi 4t = 8\pi t`

taking
`\pi`= 3.14

radius of circular wave after t second will be =
`8*3.14*t= 25.12t`

Thus, circumference of the circle after t seconds =
`8\pi t` = 25.12t