Question

When a beam of light is incident on a surface, it delivers energy to the surface. The intensity of the beam is defined as the energy delivered per unit area per unit time.
What is the unit of intensity, expressed in SI base units?​

Answer 1

Answer:

Kg

Explanation:

Given that the definition of intensity is:

The intensity of the beam is defined as the energy delivered per unit area per unit time. That is,

I =( E × t)/A

Which can expressed as

I = J/m^2/s

The S.I Units of

Energy is Joule = kgm^2s^-1

Area A = m^2

Time t = s

Intensity I = kgm^2s^-1 × m^-2 × s

Intensity I = kg

The cubic metres and seconds are cancelled out

Therefore, the S.I units of intensity is kg