What is speed vs velocity in physics?

📚 What is Speed?

Speed is a scalar quantity that refers to 'how fast an object is moving'. Speed is the rate at which an object covers distance. It is a scalar because it has magnitude only.

• 📏 Definition: Speed is the distance traveled per unit of time.
• 🔢 Formula: $Speed = \frac{Distance}{Time}$
• 🚗 Units: Common units include meters per second (m/s), kilometers per hour (km/h), and miles per hour (mph).
• ➕ Scalar: Speed only has a magnitude (a numerical value); it does not have a direction.
• ⏱️ Example: A car traveling at 60 km/h.

📚 What is Velocity?

Velocity is a vector quantity that refers to 'the rate at which an object changes its position'. Velocity is the rate at which an object changes displacement. It is a vector because it has both magnitude and direction.

• 🧭 Definition: Velocity is the rate of change of displacement. It includes both speed and direction.
• ➗ Formula: $Velocity = \frac{Displacement}{Time}$
• ✈️ Units: Common units are the same as speed: m/s, km/h, mph, but the direction must also be specified.
• ➡️ Vector: Velocity has both magnitude and direction.
• 🗺️ Example: A car traveling at 60 km/h East.

📝 Speed vs. Velocity: The Key Differences

💡 Key Takeaways

• ✅ Direction Matters: The main difference is that velocity includes direction, while speed doesn't.
• 🔄 Constant Speed, Changing Velocity: An object can have constant speed but changing velocity if its direction is changing (e.g., a car going around a circular track at a constant speed).
• 📍 Displacement vs. Distance: Velocity uses displacement (the shortest distance between two points), while speed uses the total distance traveled.
• 🧪 Real-World Applications: Understanding the difference is crucial in physics problems involving motion, especially when dealing with vectors.