Physics
posted by Alex .
6) If a flea has a mass of 2.0x10^2 micrograms jumps vertically to a height of 65mm and 75% of the energy comes from elastic potential energy stored in the protein, determine the initial quantity of elastic potential energy.
drwls said to use:
(1/2)M g H = (0.75)E where E is the potential energy stored in protein and H is the height that the flea can jump.
I don't understand how that would work. Also would you convert 2.0x10^2ug to kg?

He is right. The gravitational PE the flea gains is equal to .75 * the initial stored energy. BTW: energy stored in protein is chemical energy, not elastic.
Yes, convert grams to kg, and H to meters, and of course, g is 9.8m/s^2. 
I got 8.4x10^8. Is that right?

Energy=.5*200E6*.065/.75
paste .5*200E6*.065/.75 into the google search engine.