Question

Riding in a hot air balloon is an exciting way to travel. Passengers climb into a basket that is attached to a huge balloon with

cables. The balloon is filled with hot air. The burning gas and heat inside the huge balloon make it lighter than the surrounding air.
The balloon rises and lifts the passengers into the sky. The pilot does not know where the balloon will go. It floats gently in the
direction the wind blows. The passengers enjoy a fun ride with a terrific view of the land and water below them. When the pilot is
ready to land, he or she lets the air cool inside the balloon. The balloon starts to become heavier and begins going back down to
land. A group on the ground follows the balloon in a car and watches where it lands. Part of the excitement is that no one knows
exactly where a hot air balloon will land.
The main idea of this passage is
А. hot air balloon passengers ride in baskets
B. hot air balloons are lifted by hot air
c. groups of people follow balloons in cars.
D. traveling in a hot air balloon is exciting

Answer 1

Hot air balloons rise due to the buoyant force created when the air inside the balloon, heated and made less dense by the burner, contrasts with cooler and denser outside air. The pilot controls altitude by adjusting the air temperature inside the balloon.

Hot air balloons move smoothly in the air due to the principles of buoyancy and the behavior of gases. As the air inside the balloon is heated by a burner, it expands and becomes less dense than the cooler air outside the balloon. This difference in density creates a buoyant force that lifts the balloon into the air. By controlling the temperature of the air inside the balloon, the pilot can make the balloon rise or descend. This is because the internal air temperature affects the balloon's density and thus its altitude. For landing, cooling the air inside the balloon reduces the buoyant force, allowing the balloon to descend smoothly.