Sound travels slow in cold air. why does the speed of sound depend on air temperature?

According to the tide table below what time of day will the highest tide occur?

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 380j of energy to the room?

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?