5 Physical Science questions

Answer all the questions Question- 5 (chapter-V) 1. When a mercury-in-glass thermometer is heated, its mercury column goes down briefly before rising. Why? 2. When water is boiled in a pan, the bubbles of steam increase in size as they rise through the water. Why? 3. You can safely put your hand inside a hot oven for a short time, but even a momentary contact with the metal walls of the oven will cause a burn. Explain. 4. What does Archimedes Principle state? Explain what force if felt when you dive in a pool of water? 5. If you wish to speed up the rate at which potatoes are cooking in a pan of boiling water, would it be better to turn up the gas flame or use a pressure cooker?