velocity

Everyday

1. Velocity is speed in a particular direction. tree →
2. In everyday use, velocity means speed, especially high speed. tree →

In the lessons

In science and maths lessons, speed tells how fast something goes; velocity tells how fast and which way. Velocity is measured in metres per second (m/s). If you run round a track at the same speed, your velocity keeps changing because your direction changes. Escape velocity is the speed a rocket needs to leave Earth's pull.

Examples

• The ball left the bat at a high velocity. tree →
• Velocity is speed in a given direction. tree →
• A rocket needs a huge velocity to escape Earth. tree →
• The river's velocity was faster in the middle. tree →
• We measured the velocity of the toy car in metres per second. tree →
• Wind velocity was 50 kilometres per hour from the north. tree →

Note

Mostly uncountable; plural velocities in science. In maths problems, velocity = distance (displacement) divided by time; a negative velocity means moving the opposite way. Speed has no direction; velocity does.