Question

The minimum speed needed for an object to escape from the gravitational influence of the earth is:

• A. Orbital velocity
• B. Escape velocity
• C. $v_e=\sqrt{\frac{2gM}{R}}$
• D. $v_0=\sqrt{\frac{gM}{R}}$

Answer 1

Answer: (B), (C)

The correct options are
B

Escape velocity

C

$v_e=\sqrt{\frac{2gM}{R}}$

The escape velocity $\left(v_e\right)$ is the minimum speed needed for an object to escape from the gravitational influence of the earth.
$v_e=\sqrt{\frac{2GM}{R}}$
The escape velocity from the earth is about 11.186 km/s.

Orbital Velocity $\left(v_o\right)$ is the speed with which objects travel in uniform circular motion around the earth. The velocity of this orbit depends on the distance from the object to the center of the earth.
$v_0=\sqrt{\frac{GM}{R+h}}$