It all depends on the SIZE of the balloon.
If the balloon is made of really tough rubber, and it holds the helium in the same volume as the solid iron block, then the buoyant force of the atmosphere is the same for both objects.
But if the balloon is just some flimsy stuff, and it lets the helium expand to a much bigger volume than the iron block, then the buoyant force on the balloon is greater than the buoyant force on the solid iron block.
In fact, it DOESN'T MATTER what's in the balloon and what's in the block. It doesn't matter whether either one of them is solid, liquid, or gas, and it doesn't matter whether they have the same or different mass.
Whichever one has greater VOLUME has a greater buoyant force of atmosphere acting on it.
Answer:
Explanation:
The buoyant force depends on the volume of the body
Buoyant force = Volume immersed x density of fluid x gravity
So, the density of fluid that means air is same for both the cases, but the volume of 1 kg helium balloon is more than the density of iron, so the buoyant force on helium is more than the buoyant force on iron.
