How heavy is the world? how do you work it out?

Answer 1

The mass of Earth is about 5.9742 × 10^24 kilograms.

"The mass of the Earth may be determined using Newton's law of gravitation. It is given as the force (F), which is equal to the Gravitational constant multiplied by the mass of the planet and the mass of the object, divided by the square of the radius of the planet. We set this equal to the fundamental equation, force (F) equals mass (m) multiplied by acceleration (a). We know that the acceleration due to gravity is equal to 9.8 m/s2, the Gravitational constant (G) is 6.673 × 10-11 Nm2/kg2, the radius of the Earth is 6.37 × 106 m, and mass cancels out. When we rearrange the equation and plug all the numbers in, we find that the mass of the Earth is 5.96 × 1024 kg."

Answer 2

Hi. With eyes like that how could Geolicious be wrong! A more basic question might be how "g" was established. Scientists used a torsion scale to measure the gravity between two heavy lead balls. This kind of scale uses a fine wire to hold the lead in position. The wire twists a bit under the slightest force and was capable of measuring the attraction between the weights.