The rate of change of position is called what?

• A. Velocity
• B. Acceleration
• C. Mass
• D. Speed

Answer: (D)

Velocity describes how fast position changes and in which direction. It’s a vector, so it combines speed with direction. For example, traveling north at 10 meters per second means your velocity is 10 m/s north. Speed, on the other hand, is only how fast you’re moving and doesn’t say anything about direction. Acceleration is the rate at which velocity itself changes, like speeding up or slowing down, and mass is a measure of how much matter something contains. So the rate of change of position is velocity.