There was no additional air in the tire the second time Lawrence checked the air pressure, but something did change between the two measurements. The tires had rolled over 10 miles of road on the trip to school. Any time one surface moves over another, it causes friction. Friction is a force that opposes the motion of two surfaces that are touching, and friction between two surfaces always generates heat. Quickly rub your hands together and you’ll feel the heat generated by the friction between them. As the tires moved over the road, friction between the tires and road generated heat. In short, the tires got warmer and so did the air inside them.
Mike noticed his low tire pressure light was on when he left work. After driving for 30 minutes Mike decided to stop and check his tire pressure even though the light had gone off,  it was at 35 psi so he didn't add air. When he started his car the next morning his his low tire pressure light was on.
Did the air in Mike's tire heat up or cool down overnight?