Matter, Mass and Energy

What if it is not matter? (often people say - it doesn't matter!)

Mass is the amount of stuff an object is made up of.

What is true about matter?

Mass is a key characteristic of matter.

On the surface of Earth, a spacecraft has a mass of 2.00 x 10^4 kilogram. What is the mass of the spacecraft at a distance of one Earth radius above Earth's surface?

Mass of an object is really a measure of its energy.

The source of all energy on earth is the conversion of _______.

Albert Einstein famous formula E=mc^2 relates mass of an object with its energy.

Albert Einstein's discovery of his famous formula E=mc^2, which relates that the mass of an object is really a measure of its energy, has paved the way for tremendous innovation like...