Light globe brightness change with voltage

[Crushgear64]

Homework Statement

If a 6v incandescent globe is running at 6v with 0.6amps has a 0.909 resistor introduced into it's circuit which drops the voltage across it to 5.501v and 0.55amps how much does the brghtness change?

The Attempt at a Solution

5.501*0.55/6*0.6 original brightness. Is it as simple as this? Because I know globes are a non-ohmic conductor.

 

[CWatters]

There is enough information in the question to allow you to calculate if the resistance has changed.

I believe your approach is correct (eg ratio of power) but perhaps add what other assumption you have to make about a bulbs brightness.