Multiple choice general knowledge A cough releases an explosive charge of air that moves at speeds up to -- mph. 40 60 20 30 Reveal answer Fill a bubble to check yourself B Correct answer Explanation A cough can expel air at speeds up to 60 mph (approximately 96 km/h). The force of a cough is generated by the diaphragm and respiratory muscles suddenly contracting to expel irritants. This high velocity helps clear the airways effectively.