Question
Hot air rises because it has expanded. It then displaces a greater volume of cold air, which increases the buoyant force on it.
1. Calculate the ratio of the buoyant force to the weight of $50.0^\circ\textrm{C}$ air surrounded by $20.0^\circ\textrm{C}$ air.
2. What energy is needed to cause $1.00 \textrm{ m}^3$ of air to go from $20.0^\circ\textrm{C}$ to $50.0^\circ\textrm{C}$?
3. What gravitational potential energy is gained by this volume of air if it rises 1.00 m? Will this cause a significant cooling of the air?
1. $1.10$
2. $2.79 \times 10^4 \textrm{ J}$
3. $12.7 \textrm{ J}$
Solution Video