Why is the power of a lightbulb that converts electrical energy at a rate of 100 joules per second is 100 watts
The light bulb takes up 100 joules electrical energy in 1s.This means that the light bulb which now has 100 joule extra energy converts its energy into different forms like Heat and Light Energy.This converted energy is due to the work done by the Bulb in 1s. But work done in 1s is called POWER.PS- Power is also defined as the ENERGY CONSUMED PER SECOND.This makes understanding it lot easier.
Joules and watts are closely related,as they measure the amount of energy transferred by one amp at the resistance of one ohm.
The reason the power of a light bulb is in watts is because it is the derived unit of power. It is usually a measures the rate of energy conversion. It is the internationally accepted measuring unit of electricity.