Instantaneous Speed: The speed of an object at a particular instant. It's how fast the object is moving at that exact moment, rather than over an entire journey or time interval.

Practical Examples

1. Driving a Car

• When you look at your car's speedometer, it shows you the instantaneous speed, which is how fast you're going at that exact moment.

1. Running or Cycling

• If you're tracking your run or bike ride, a fitness app may show your speed at different moments. This speed at each moment is your instantaneous speed.

An object is travelling at a steady or constant speed when its instantaneous speed has the same value throughout its journey. For example, if a car is travelling at a constant speed the reading on the car's speedometer does not change. The speedometer reads the speed of the car at each moment in time throughout the car's journey. In cases like this, where the motion involves constant speed, the instantaneous speed of the object can be worked out using the relationship:

Formula