What is the unit of speed?

The unit of speed is metres per second (m/s) or kilometres per hour (km/h).

Speed is a measure of how quickly an object moves from one place to another. In physics, speed is defined as the distance travelled divided by the time taken to travel that distance. The standard unit of speed in the International System of Units (SI) is metres per second (m/s). This means that if an object travels one metre in one second, its speed is 1 m/s.

Another common unit of speed, especially in everyday life, is kilometres per hour (km/h). This unit is often used for measuring the speed of vehicles like cars and bicycles. For example, if a car travels 60 kilometres in one hour, its speed is 60 km/h. To convert between these units, you can use the fact that 1 m/s is equal to 3.6 km/h. So, if you know the speed in m/s, you can multiply by 3.6 to get the speed in km/h, and vice versa.

In some contexts, you might also encounter miles per hour (mph), especially in countries like the United States. However, for GCSE Physics, you will primarily use metres per second and kilometres per hour.

Understanding the units of speed is crucial for solving problems in physics. For example, if you know the distance an object has travelled and the time it took, you can calculate its speed using the formula: speed = distance / time. This formula helps you analyse various scenarios, such as how long it will take to travel a certain distance at a given speed or how far an object will travel in a specific amount of time.

By mastering the concept of speed and its units, you'll be better equipped to tackle a wide range of physics problems and understand the motion of objects in the world around you.