## Helium Balloon

Under standard conditions, the density of air is 1.293 kg/m3 and that of helium is 0.178 kg/m3. A spherical helium balloon lifts a basket plus cargo of mass 266.0 kg.

What must be the minimum diameter of the spherical balloon?

What must be the minimum diameter of the spherical balloon?

**7.69 m**## Discussion

**NEW**

how do you go about starting this?

**NEW**

*Anonymous 2*

First, solve for the volume of the balloon.

V*(a-b)= mass, where a is the density of air and b is the

density of helium and mass is left in kg.

Remember the formula for volume of a sphere is V=4/3(pi)

r^3. Set the volume you just got on one side and solve for

r, but they are asking for diameter so don't forget to

multiply the answer by 2.