Escape velocity is the minimum velocity that an object must reach to break free from the gravitational pull of a celestial body, such as a planet, moon, or star, without any further propulsion. It allows an object to escape the gravitational field of the celestial body and travel into space. The formula for escape velocity can be derived from Newton’s law of universal gravitation and is given as follows:
Where:
- Vesc is the escape velocity (in meters per second, m/s).
- G is the gravitational constant, approximately equal to 6.674 × 10^(-11) N m²/kg².
- M is the mass of the celestial body (in kilograms, kg) that an object is trying to escape from.
- R is the distance from the center of the celestial body to the object (in meters, m).
In SI (International System of Units), the units for each term are as follows:
- Gravitational constant G: N m²/kg²
- Mass M: kg
- Distance R: m
- Escape Velocity Ve: m/s
So, when you plug in the values with these units into the formula, you’ll get the escape velocity in meters per second.
Keep in mind that the escape velocity can vary depending on the celestial body you’re considering, as it depends on the mass and radius of that body. For example, the escape velocity on Earth is approximately 11.2 kilometers per second (km/s), while the escape velocity on the Moon is much lower, at about 2.38 km/s, due to the Moon’s smaller mass and radius.