Vastigheten

Vastigheten describes how quickly an object moves, defined as the rate at which distance changes with time. In physics, it is typically treated as a scalar quantity, meaning it has magnitude but no direction. The instantaneous vastigheten is the speed at a specific moment, while the average vastigheten over a time interval is the total distance traveled divided by the elapsed time.

Its SI unit is the meter per second (m/s), but kilometres per hour (km/h) and miles per hour (mph) are commonly used in everyday life. To convert, multiply by 3.6 to go from m/s to km/h, or divide by 3.6 to go from km/h to m/s.

Vastigheten is related to but distinct from velocity. Velocity combines speed with a direction and is a vector quantity. Speed measures how fast an object moves, while velocity tells how fast and in what direction.

Measurement and applications: In vehicles, a speedometer displays instantaneous vastigheten. Radar guns and GPS-based systems estimate speed for law enforcement and navigation. In physics and astronomy, vastigheten helps describe motion, including uniform motion, acceleration, and orbital dynamics.

Relativistic note: According to special relativity, no object with mass can reach or exceed the speed of light in vacuum, and measurements of time and length depend on the observer’s motion at high speeds, affecting perceived vastigheden and related quantities.