If it is the first day of Winter in the Northern Hemisphere, what day is it in the Southern Hemisphere?

A248-g piece of copper is dropped into 390 ml of water at 22.6 °c. the final temperature of the water was measured as 39.9 °c. calculate the initial temperature of the piece of copper. assume that all heat transfer occurs between the copper and the water. remember, the density of water is 1.0 g/m

The energy equivalent of the rest mass of an electron is

Select all the correct answers. which three statements about electromagnetic radiation are true?