The terms weight and mass are often used incorrectly. Phrases like ‘a bag of sugar weighs 1 kg’ are not scientifically correct. This means that a 1 kg mass would be attracted to Earth by a force of 10 ...

Barry Lienert, a geophysicist at the University of Hawaii, provides the following explanation. We start by determining the mass of the Earth. Issac Newton's Law of Universal Gravitation tells us that ...

Gravity is the attraction between two objects that have mass or energy, whether this is seen in dropping a rock from a bridge, a planet orbiting a star or the moon causing ocean tides. Gravity is ...