What is the escape velocity from the surface of the Earth?

Solution

1. The escape velocity $v_e$ is defined by the formula $v_e=\sqrt{\frac{2GM}{R}}$, where $G$ is the gravitational constant, $M$ is the mass of the Earth, and $R$ is the radius of the Earth.
2. Substituting the known values for Earth's mass ($M\approx 5.97\times 10^{24}\text{ kg}$) and radius ($R\approx 6.37\times 10^6\text{ m}$), we calculate the velocity.
3. The resulting value is approximately $11,186\text{ m/s}$, which rounds to $11.2\text{ km/s}$.
4. Hence the answer is (A).