Need confirmation- Energy and PEgrav

[jakeowens]

The energy content of beer is about 1.8e6 J/kg. If that energy could be turned completely into gravitational PE, how much beer would we need to raise a 0.9 kg mass 1.5 km into the air?

What i did for this, was just used the equation PEgrav=mg*delta H.

so .9kg*9.81m/s^2*1500m =13243.5 kgm^2/s^2.

So i set that =1.8e6J/kg, and divided 13243.5 by 1.8e6, giving me .0073575kg.

So, i need 7.3575 grams of beer correct?

It just seems really low to me so just looking for confirmation.

Thanks

 

[mezarashi]

Not at all. You need 13243.5 Joules of energy, and there is what? 18000000 Joules per kilogram in beer? Looking at the numbers side by side

13243.5 - Needed
1800000 - Provided per kg
1800.0 - Provided per gram
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[jakeowens]

oh alright, thanks :D

I was right, just hadn't thought about it like that.