What if I filled my vehicle with helium

[HellToupee]

I'm no physicist but find it fascinating... so as a joke/problem I am trying to work out if filling my car's body panels, trunk, backseat area with helium or hydrogen would improve 0-60 performance and why. Assuming that I have hydrogen tight air bladders and neglecting weight distribution from front to back. Can anyone shed light?

 

[mathman]

My guess is that the effect will be negligible. The cars mass will be about the same - you could make a bigger difference by removing the spare tire.

 

[phyRob]

Your truck will be lighter and as a result will have less traction. I doubt that you could fit a significant amount of gas into the panels to make a big difference. Plus the bladders will add weight( offsetting the reduction from the gas) to the truck - you're probably thinking of something like helium balloons.

 

[HellToupee]

But you think there would be a positive (though negligable) improvement in acceleration due to the reduced mass or is that a falsehood?

 

[Drakkith]

But you think there would be a positive (though negligable) improvement in acceleration due to the reduced mass or is that a falsehood?

Adding any kind of bladders or something to keep the gas inside would probably offset any negligible gain in performance.

 

[phyRob]

Compared to the mass of the truck, the amount of mass removed by using helium would be extremely small. You could do a rough calculation of how much the air weighs in the trunk and backseat area. Specific weight of air at 70F is about 0.075 lb/cuft.

 

[HellToupee]

On a related note,
does it take less force to move a 20 ton blimp that is in the air filled with hydrogen than it does to move it on the ground ignoring friction from contact with the ground?

 

[yungman]

I'm no physicist but find it fascinating... so as a joke/problem I am trying to work out if filling my car's body panels, trunk, backseat area with helium or hydrogen would improve 0-60 performance and why. Assuming that I have hydrogen tight air bladders and neglecting weight distribution from front to back. Can anyone shed light?

Helium?! You might talk funny!

 

[phyRob]

On a related note,
does it take less force to move a 20 ton blimp that is in the air filled with hydrogen than it does to move it on the ground ignoring friction from contact with the ground?

Air density decreases as you go up, so there is less drag at higher altitudes.

 

[thopsy]

Assuming your car has a volume of 10 m3, if you filled *the whole car with helium* instead of air, you would save:

At ambient pressure, air density is about rho_air = 1.3 kg/m3, helium density is about rho_He = 0.17 kg/m3

m_air = V*density = 10*1.3 = 13 kg;
m_He = 1.7 kg;

You would save only around 10 kg, for filling your whole car! Probably not worth it. Filling your tires will have a little more effect, since the gas is pressurized so the weight savings will be multiplied. Also the inertia of the tires may be decreased. Still, it will be negligible.