AMass
BGravitational pull
COrbital velocity
DAtmospheric drag
Answer:
C. Orbital velocity
Read Explanation:
Orbital Velocity: The Key to Satellite Orbits
Understanding Orbital Velocity
Orbital velocity is the speed an object must attain to orbit a celestial body (like a planet or star) in a stable circular or elliptical path.
It is the precise speed at which the satellite's forward momentum perfectly balances the gravitational pull of the central body.
Without this specific velocity, the satellite would either fall back to the central body or escape into space.
Physics Behind the Orbit
Centripetal Force: The gravitational force exerted by the central body acts as the centripetal force, continuously pulling the satellite towards the center.
Inertia: The satellite's inertia, a property of matter that resists changes in its state of motion, causes it to want to continue moving in a straight line.
Balance: Orbital velocity is the speed where these two forces (gravity pulling inwards and inertia wanting to move outwards in a straight line) are in equilibrium, resulting in a continuous curved path around the central body.
Factors Affecting Orbital Velocity
Mass of the Central Body (M): A more massive central body exerts a stronger gravitational pull, requiring a higher orbital velocity.
Distance from the Central Body (r): The further away a satellite is, the weaker the gravitational pull, and thus a lower orbital velocity is needed for a stable orbit.
Mathematical Representation
For a circular orbit, the orbital velocity (v) can be calculated using the formula: v = sqrt(GM/r), where:
G is the gravitational constant (approximately 6.674 × 10-11 N m2/kg2).
M is the mass of the central body.
r is the orbital radius (distance from the center of the central body to the satellite).
This formula highlights that orbital velocity is independent of the satellite's mass.