Question

Question #b0cef

Answer 1

The mass of air inside the balloon is 630 kg.
The total weight of the balloon is 8900 N.

Explanation:

So, you know that you have a balloon filled with air. The volume of the balloon is equal to `"700 m"^3`.

The density of the air will tell you what mass of air occupies exactly `"1 m"^3`. Since you know the volume of the balloon, you can use the density of the air to help you determine what the mass of the air is.

`700cancel("m"^3) * "0.90 kg"/(1cancel("m"^3)) = color(green)("630 kg")`

To get the total weight of the balloon, you need to calculate its total mass first. Since the material and equipment add a mass of 280 kg to the mass of air, the total mass will be

`m_"total" = m_"air" + m_"not air"`

`m_"total" = 630 + 280 = "910 kg"`

This means that the total weight of the balloon will be

`G_"total" = m * g = "910 kg" * 9.8"m"/"s"^2 = "8918 N"`

I'll leave both values rounded to two sig figs, despite the fact that you only gave one sig fig for the volume of the balloon.

`G_"total" = color(green)("8900 N")`