Nanometers measure the length of very small magnitudes, such as wavelengths. A joule, abbreviated as J, is a unit of energy in the metric system. The conversion between nanometers and joules is important in physics because scientists often need to calculate the energy of electromagnetic radiation from the wavelength. To do this, you apply the following formula derived from Planck's equation:
Identify Planck Constant Value
Use Speed of Light Constant
Multiply Planck by Speed of Light
Calculate Wavelength in Meters
Divide Product of Constants by Wavelength
Retrieve the Planck constant value: h = 6.626 069 57 x10-34 J s.
Get the speed of light constant: c = 299,792,458 m/s.
Multiply the Planck constant by the speed of light. Work out:
Divide the wavelength in nanometers by 109 to calculate the value in meters. For example, the wavelength of 500 nm corresponds to:
Divide the product of the constants by the wavelength in meters to calculate the energy in Joules. In this example, the energy is: