Velocity

Definition

Velocity is the speed of an object in a specific direction. It is a vector quantity, meaning it has both magnitude and direction.

5 Must Know Facts For Your Next Test

1. Kepler's laws of planetary motion are based on the concept of velocity and how planets travel in elliptical orbits with varying speeds.
2. In Newtonian mechanics, velocity plays a crucial role in understanding the gravitational forces acting between celestial bodies.
3. The orbital velocity of an object is the minimum velocity needed to achieve orbit around a larger body, like a planet or star.
4. Escape velocity is the speed required for an object to break free from the gravitational pull of a celestial body without further propulsion.
5. Relative velocity helps astronomers determine the motion of objects in space relative to each other, which is essential for understanding complex movements in multi-body systems.

Review Questions

• What distinguishes velocity from speed?
• How does Kepler’s second law relate to the concept of velocity?
• Why is escape velocity important when considering spacecraft missions?

Related terms

Speed: The rate at which an object moves regardless of its direction.

Acceleration: The rate of change of velocity over time.

Orbit: The curved path that an object follows as it revolves around another object due to gravity.