MCQ Detailed View

Escape velocity is the minimum speed required for a body to overcome the gravitational pull of the Earth and enter space without further propulsion. This velocity depends on the planet’s mass and radius, and it ensures that the object has enough kinetic energy to counteract gravitational potential energy.

For Earth, the escape velocity is approximately 7 miles per second (about 11.2 kilometers per second). Any object launched at this speed can leave Earth’s gravitational influence. If the object’s speed is lower than this, gravity will eventually slow it down and cause it to fall back to the surface.

The escape velocity is calculated using the formula:

ve=2GMRv_e = \sqrt{\frac{2GM}{R}}ve=R2GM

where $G$ is the gravitational constant, $M$ is the Earth’s mass, and $R$ is the radius of Earth. This formula shows that escape velocity is independent of the mass of the object; it only depends on the properties of the planet.

Understanding escape velocity is important in physics and space science. Rockets and spacecraft must reach at least this velocity, often using additional propulsion to overcome air resistance and other practical challenges. The concept also demonstrates the relationship between kinetic energy and gravitational potential energy, illustrating fundamental principles of mechanics.

In summary, a body must be thrown upward at approximately 7 miles per second to escape the Earth’s gravity. This concept is critical in understanding planetary physics, orbital mechanics, and space exploration.