In a closed room at sea level, Sunita is wearing a balloon hat. If she ascends to the top of a high mountain with the same balloon hat, what would likely happen to the hat and why, assuming the temperature remains the same? Provide a very brief response.
The balloon hat would expand as Sunita ascends the high mountain. This occurs because at higher altitudes, the atmospheric pressure is lower than at sea level. The air inside the balloon was initially at equilibrium with the sea level atmospheric pressure, but as the outside pressure decreases with altitude, the air inside the balloon pushes outward more strongly since there's less atmospheric pressure to counteract it. As long as the balloon's material can stretch without popping, the balloon will expand.