In physics, we often discuss speed and velocity. They might seem similar, but they’re not. Speed tells us how fast something moves over time, while velocity tells us how fast it moves and in what direction. For example, driving 60 miles per hour is your speed. But velocity includes both speed and direction. So, driving 60 miles per hour north is your velocity.
Working with Speed Formulas
Speed is about how fast something moves. The basic formula for average speed is distance over time. For example, driving 240 kilometers in 3 hours means your average speed is 80 km/h. Speed is a scalar quantity, which means it has only magnitude, not direction.
Solving Velocity Problems
Velocity, however, is a vector quantity. It includes both speed and direction. To find the average velocity, divide displacement by time. For example, walking 3 km east in 30 minutes means your average velocity is 6 km/h east.
The Importance of Direction in Velocity
Direction is what sets velocity apart from speed. Two cars might travel at the same speed, but their velocities are different if they’re going in opposite directions. Velocity is so important in physics – it gives us a complete picture of motion.
“Velocity is not just about how fast you’re going, but where you’re heading.”
Converting Between Speed and Velocity
Changing between speed and velocity means looking at direction. Here’s a quick guide for common conversions:
| Speed | Velocity |
|---|---|
| 20 m/s | 72 km/h (in a specific direction) |
| 120 km/h | 33.33 m/s (in a specific direction) |
| 300 knots | 345 mph (in aviation, with direction) |
