units for energy

$E=hv$

Elyssa Smith 4B
Posts: 58
Joined: Wed Sep 18, 2019 12:22 am

units for energy

What are the units for energy in the E=hv equation? Is it Joules or Joules/photon?

Anika Chakrabarti 1A
Posts: 86
Joined: Sat Aug 24, 2019 12:17 am

Re: units for energy

The unit is J, but in the E=hv equation you are finding the energy of a photon, so technically this value means the amount of energy per photon. I think you can just write J in your answer though.

Jared Khoo 1G
Posts: 90
Joined: Wed Sep 18, 2019 12:16 am

Re: units for energy

The unit for energy is Joules, which is equivalent to a Newton*meter. Planck's constant h is in the units of m2kgs-1 and the unit for v frequency v is s-1. Multiplying these together you would get m2kgs-2. As a newton is in the units of kgms-2, you can see that this equation indeed does find Joules, or N*m.