Skip to content

Comment on Gravity Light - Alternative form of lighting to replace Keroseneparent

Comments

Line three: you write

   Energy stored E = mgh (300 J)
but by substitution
   Energy stored E = 10 (kg) (9.8 m/sec) 3 (meters)
                     2940 J
2940/1800 is 1.6W

Check your math. I used 10 instead of 9.8 for g since I was just doing a "back of the envelope" calculation. 10 x 10 x 3 = 300.

sigh, you are absolutely correct. The rounding up messed with my brain I saw the 300 and thought "oh that is just 10 * 3 (brain fart) he didn't add in the 9.8"

AND I have to correct mine too since I used 180 for time (30 * 6 rather than 30 * 60)

AboutSource Built by g1lg1l

Hackerly is an independent reader for Hacker News, built on the public HN API. Not affiliated with Y Combinator.