To describe speed, two essential units of measurement are required: distance and time. Speed is defined as the rate at which an object covers distance over a specified period.
For distance, commonly used units include kilometers (km) or miles (mi). For time, the standard units are seconds (s), minutes (min), or hours (h). When combined, these units create the formula for speed, typically expressed as:
Speed = Distance / Time
For example, if a car travels 100 kilometers in 2 hours, its speed can be calculated as 100 km ÷ 2 h = 50 km/h. This shows that units of distance and time are fundamental in accurately conveying the concept of speed.