Question

The dimension of radiation pressure is -

• A. $\left[M{L}^1{T}^2\right]$
• B. $\left[M{L}^1{T}^{-2}\right]$
• C. $\left[M{L}^{-1}{T}^2\right]$
• D. $\left[M{L}^{-1}{T}^{-2}\right]$

Answer 1

The correct option is D $\left[M{L}^{-1}{T}^{-2}\right]$

We know that, radiation pressure for a perfectly absorbing surface is given by,

$p=\frac{I}{c}=\frac{F}{A}$

So,

$\left[p\right]=\frac{\left[F\right]}{\left[A\right]}=\frac{\left[M{L}^1{T}^{-2}\right]}{\left[L^2\right]}$

$\Rightarrow \left[p\right]=\left[M{L}^{-1}{T}^{-2}\right]$

Hence, option $\left(D\right)$ is the correct answer.