A soccer ball is inflated to a pressure of 110 kPa and left outside in the hot sun. After some time, the player notices its pressure has increased. They believe this is due to the increase in temperature inside the ball.

Explain, in terms of gas particles, why the pressure inside the ball has increased.

A student writes down a simple model of atmospheric pressure:

• The atmosphere is made up of gas molecules colliding with objects.
• The density of the air is assumed to be uniform.
• The atmospheric pressure increases as the altitude above the ground increases.

The student has made one mistake in this model.

Identify the wrong word and write the correct word to replace it.

Wrong word: Correct word: