At present, a 100 cubic meter hot air balloon is still in the air. If the known air density is 1.29 kg / cubic meter, then the hot air balloon is still in the air

At present, a 100 cubic meter hot air balloon is still in the air. If the known air density is 1.29 kg / cubic meter, then the hot air balloon is still in the air

It's the buoyancy of the balloon
F = ρ GV = 1.29 * 10 * 100 = 1290 (n)