Q. A diver 22m deep in 12°C fresh water exhales a 0.8 cm diameter bubble. What is the bubble's diameter just as it reaches the surface of the lake, where the water temperature is 25°C? Hint: suppose that the air bubble is always in thermal equilibrium with surrounding water.
Q. presumes 8 g of hydrogen is separated into electrons and protons. Assume also the protons are placed at the earth's North Pole and the electrons are placed at the South Pole. What is the resulting compression force on the Earth?