hetkeväärtus

Hetkeväärtus is Estonian for the value of a quantity at a specific moment in time. In mathematics and applied sciences, it denotes the instantaneous value of a time-dependent quantity, as opposed to its average or total over an interval. For a continuous-time function x(t), the hetkeväärtus at time t0 is x(t0). For a discrete-time signal x[k], the hetkeväärtus at index k0 is x[k0].

In practice, hetkeväärtus describes the actual reading of a variable at a given moment. Examples include the instantaneous position s(t) of a moving object at time t, or the instantaneous velocity v(t) of a rotating wheel. In electrical engineering and data analysis, the hetkeväärtus of a voltage or current signal is the value observed at the precise moment of measurement, which can differ from average, RMS, or peak values.

Measurement context often affects hetkeväärtus. Factors such as sampling rate, sensor latency, quantization, and noise can influence how accurately the instantaneous value is captured. In real-time monitoring and control systems, capturing the correct hetkeväärtus is important for timely decision-making and proper system response.

Relation to other concepts is contextual. Hetkeväärtus is distinct from the mean value over a period, from the expected value in probability theory, and from financial present value, which have different definitions and uses. The term is commonly encountered in physics, engineering, and time-series analysis to emphasize the value at a precise moment rather than over an interval.