Measuring Gravity on Earth

Gravity on Earth can be measured through gravitational acceleration, often written as g. This value describes the acceleration an object experiences on Earth because of Earth’s gravitational force. Knowing g is important because it tells us the strength of that force at Earth’s surface.

The idea ...

The Law of Universal Gravitation was the culmination of years of effort by Isaac Newton to understand the force of attraction between masses.

According to legend, when Newton saw an apple dropping from a tree he deduced that a force must draw the apple to the Earth. If this force could act at the top of a tree, it could act at even greater...