Question

A hot air balloon rises because:

Options

• Pressure inside decreases

• Heated air expands and becomes less dense

• Volume remains constant, and pressure rises

• The number of moles of gas increases

Answer 1

Heated air expands and becomes less dense

Explanation:

Heating the air inside increases its volume (V ∝ T), making it less dense than the surrounding cooler air, so the balloon floats upward.