# Amplitude & Time constant

LBRRIT2390

## Homework Statement

A gust of wind hits a flagpole and starts it oscillating. After 10 s, the amplitude of its motion has decreased to 25% of its initial value.

What is the value of the time constant?

## Homework Equations

xmax(t) = Ae$$-t/\tau$$

## The Attempt at a Solution

I know that the answer is 7.2s, but how do I find it?

How do I manipulate the above equation?