## helium balloon

I can't seem to figure this simple helium balloon problem out? I would really appreciate some help? Thanks!

Estimate the volume of a helium-filled balloon at STP if it is to lift a payload of 500 kg. The density of air is 1.29 kg/cubic meter and helium has a density of .178 kg/cubic meter.

I think you use a formula like force bouyancy equals density of air times volume times gravity????????? but not quite sure.

 PhysOrg.com science news on PhysOrg.com >> Heat-related deaths in Manhattan projected to rise>> Dire outlook despite global warming 'pause': study>> Sea level influenced tropical climate during the last ice age
 let V : Volume a= density of air b= density of He we have Code:  V*a=500*103+V*b
 How are you supposed to solve this equation with two unknowns?

## helium balloon

only V is unknown

 How do you solve V(1.29)= 500000+V(0.178) and is this really your answer?????????

 Originally posted by nsw How do you solve V(1.29)= 500000+V(0.178) and is this really your answer?????????
sorry the units of density are in Kg/m^3 so the equation will be

(1.29-0.178)V=500

V=450 m3

 Where does the 500 come from?
 isn't it the weight of the payload
 Oh Yah! Thanks a Bunch!
 The values: Balloon diameter : 100 feet Balloon weight : 10,000 pounds Payload weight : 6,000 pounds Lifting gas : Helium Air density at ground level : .0625 lbs/cubic foot Temperature is constant At what altitude does the balloon fly? So far I've got: h = alpha [0.862 - (16,000 lbs/ mass of air)] I'm not even sure what the variables are, I was given 47 different formulas to determine the answer to this question, none of which are helping whatsoever.

Recognitions:
Gold Member
Science Advisor
 Quote by footos66 The values: Balloon diameter : 100 feet Balloon weight : 10,000 pounds Payload weight : 6,000 pounds Lifting gas : Helium Air density at ground level : .0625 lbs/cubic foot Temperature is constant At what altitude does the balloon fly? So far I've got: h = alpha [0.862 - (16,000 lbs/ mass of air)] I'm not even sure what the variables are, I was given 47 different formulas to determine the answer to this question, none of which are helping whatsoever.
use bouyancy formula.

 Which is: mass of air (at Height, h) = [mass of payload+mass of balloon+mass of lifting gas] is that the right one?
 Thread Tools

 Similar Threads for: helium balloon Thread Forum Replies Introductory Physics Homework 8 Introductory Physics Homework 10 Introductory Physics Homework 1 Engineering, Comp Sci, & Technology Homework 1 Introductory Physics Homework 4