Choose the main pattern of organization of the passage. The…
Choose the main pattern of organization of the passage. The rubber balloon is an interesting elastic object. As an elastic balloon is inflated with helium and stretched away from its initial shape, the rubber exerts a force inward to restore equilibrium. As a result, each region of the balloon’s surface experiences three forces: an outward force from the pressure of helium inside, an inward force from the elastic skin of the balloon itself, and an inward force from the pressure of air outside. Once the balloon stops expanding and reaches a new state of equilibrium, it must be experiencing zero net force; the outward force must balance the two inward forces. Therefore, the pressure of the helium inside the balloon must be somewhat greater than the pressure of the outside air.