# Homework Help: Estimate the energy stored in a match

1. Sep 25, 2011

### paco_uk

1. The problem statement, all variables and given/known data

This is for a class to learn about making order of magnitude estimates. I want to estimate the amount of energy released by burning a match. Googling gives an answer of about 1BTU (just over 1kJ) but I can't think how to estimate it from general knowledge.

2. Relevant equations

3. The attempt at a solution

I considered trying to compare the power output of a match to that of a lightbulb. I guessed that a match would be at least a factor of 10 less bright than a 100W lightbulb.

This would give a match a power of 10W so assuming it burns for 10 seconds that would make 100J - a lot less than the correct answer.

I guess my error comes from underestimating the power output of a match but since my intuition was so wildly out, does anyone have an alternative approach that might get closer?

(It would be interesting to try and measure this value by using a lit match to heat some water and measuring the change in temperature but the spirit of this exercise is back of the envelope calculations without experiment)

Last edited: Sep 25, 2011
2. Sep 25, 2011

### Redbelly98

Staff Emeritus
You have the right idea, and you are within an order of magnitude of the given answer, so IMO that's not a bad result.

Basically, you have both the wattage or the burn time that could be different than what you said they were.

3. Sep 26, 2011

### paco_uk

Thanks, I guess given the original estimates a factor of 10 isn't that bad after all.