The point is, how do you measure the rate of moving from one instant to the next?

Power units measure the rate of energy per unit time.

An example is the measuring the rate of a chemical reaction.

The device measures the rate at which a person can exhale.

The confinement time measures the rate at which a system loses energy to its environment.

The goal was to measure the changing rate over time, and prepare a bar graph showing the results.

Problems also arise in measuring the potential rate of growth in the economy.

This kind of mutation happens all the time in living organisms, but it is difficult to measure the rate.

It measures the rate of heat transfer through a building element over a given area under standardised conditions.

It spins, at a rate measured to impressive precision, once every 0.0062185319388187 seconds.