Weight displaced and volume displaced?

[wrigglyworm]

Homework Statement

you are hovering (no acceleration) in a hot air balloon of total weight (balloon+load+hot air) 18,000 N

a) what is the weight of displaced air?

b) what is the volume of displaced air?

Homework Equations

if i knew i wouldn't be asking

The Attempt at a Solution

i also do not know

 

[superdave]

Consider Archimedes' principle and the buoyancy force.

 

[gneill]

What's are the conditions for neutral buoyancy? What's the (standard) density for air?

 

[AdrianMay]

Think about it this way. The baloon is hovering. It's not going up or down. Suppose it was slowly going down. Why would it be going down? Because every time it went down by 1mm, something heavy would be closer to the ground. That could be you in the baloon. But you're not going down. That means something equally heavy must have to go up when you go down. That's the displaced air. It must have the same weight as the thing that displaced it, because if it was lighter you'd go down, and if it was heavier you'd go up.

If you know what it weighs and you know its density, you can figure out it's volume. Do you know the density of air?

 

[rwisz]

the weight of the air that is displaced. However, I can explain the concept of weight displaced and volume displaced.

Weight displaced refers to the weight of the fluid (in this case, air) that is pushed aside or displaced by the object (hot air balloon). In other words, it is the weight of the air that would occupy the same space as the object if it were not there.

Volume displaced, on the other hand, refers to the volume of the fluid that is pushed aside or displaced by the object. In this case, it would be the volume of air that the hot air balloon takes up.

To find the weight of the displaced air, we can use the principle of buoyancy. This principle states that the weight of the fluid displaced by an object is equal to the weight of the object. Therefore, the weight of the displaced air would be equal to the weight of the hot air balloon, which is 18,000 N.

To find the volume of the displaced air, we can use the ideal gas law, which states that the volume of a gas is directly proportional to its temperature and inversely proportional to its pressure. Since the hot air balloon is hovering with no acceleration, we can assume that the temperature and pressure of the air inside and outside the balloon are the same. Therefore, the volume of the displaced air would be equal to the volume of the hot air balloon, which can be calculated using its dimensions.

In summary, the weight of the displaced air would be 18,000 N and the volume of the displaced air would depend on the dimensions of the hot air balloon.