A rectangular air mattress is 1.8 m long, 0.33 m wide…?
Thursday, September 8th, 2011 at
2:13 am
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buoyancy force = B
density water = p = 1000 kg/m^3
volume = V = 1.8 x 0.33 x 0.05 = 0.0297m^3
mass original = mo = 2.0kg
mass max = m2
g = 9.80
ok now that everything is defined lets solve
In this case, to find the max mass, we assume to submerge the matress in water
this is where B = m2g (buoyancy = to weight of matress in water)
To solve for B you must understand that B = pVg
Set equations equal to eachother, and you get this:
pVg = m2g (g’s will cancel)
(1000)(0.0297) = m2
m2 = 29.7kg
change in mass = m2 – mo = 29.7 – 2.9 = 27.7kg
hope this helps!