When you suck through a soda straw into a drink as shown in the illustration below, what causes the drink to rise into your mouth: the muscles of your lungs and cheeks or the weight of the atmosphere?

Question

Quizplus · Accepted Answer

The weight of the atmosphere is what causes the soda to rise into your mouth. When you suck through the straw, you create a lower pressure area inside the straw, and the higher pressure from the weight of the atmosphere outside the straw pushes the soda up into the straw and into your mouth. The muscles of your lungs and cheeks play a role in creating the suction force, but they are not responsible for the soda's rise into your mouth.

When You Suck Through a Soda Straw into a Drink