Question

An il film (n = 1.42) floating on water is84.8 nm thick. What is the wavelengthIN NANOMETERS of the brightest(m = 1) reflected color?(Hint: If you leave the wavelength in nm,the answer will be in nm. No conversionnecessary.)(Unit = nm)

Answer 1

Given:

n = 1.42

Thickness, t = 84.8 nm

m = 1

Let's find the wavelength in Nanometers of the brightest reflected color.

Apply the formula:

`t=(m-(1)/(2))((\lambda)/(2n))`

Where:

• t = 84.8 nm

,

• m = 1

,

• n = 1.42

Plug in the values in the formula and solve for the wavelength λ:

`\begin{gathered} 84.8=(1-(1)/(2))((\lambda)/(2*1.42)) \\ \\ 84.8=((1)/(2))((\lambda)/(2.84)) \\ \\ 84.8=(\lambda)/(2*2.84) \\ \\ 84.8=(\lambda)/(5.68) \\ \\ \lambda=84.8*5.68 \\ \\ \lambda=481.67\text{ nm} \end{gathered}`

Therefore, the wavelength is 481.67 nm.

• ANSWER:

481.67 nm