# Question #9a881

Jun 11, 2016

$0.88 s$

#### Explanation:

Distance between two adjacent crests (first and second) is equal to one wavelength $\lambda$ as shown in the figure. Distance between six adjacent crests will be $5 \lambda$.
Wavelength of the given wave $\lambda = \frac{220}{5} = 44 m m$
We know the wave equation
$v = n \lambda$ ....(1)
where $v$ is velocity and $n$ frequency of wave

We also know that time taken $T$ for one cycle of a repeating event, is the reciprocal of the frequency.
$n = \frac{1}{T}$
Equation (1) thus can be written as
$v = \frac{1}{T} \lambda$
$\implies T = \frac{\lambda}{v}$
Inserting given numbers, convert to SI units

$T = \frac{\frac{44}{1000}}{0.05} = 0.88 s$