What is the si unit for intensity? decibel mel joule watt

Watt is incorrect. The answer is: decibel

SI unit for intensity = watt/meter^2 = W/m^2

Explanation:

Intensity (Light intensity, Sound Intensity) is defined as power carried by waves through a particular area in the direction normal to that area. So mathematically it can be written as:

Intensity = Power carried by wave/Area  

I = P/A      

Units of power = watts = W

Units of Area = meter^2 = m^2

So,  

Units of power = W/m^2

Hence, SI units of power will be W/m^2.

option number c is the right answer.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2