Another flick of his mental switch and he knew exactly the velocity he would require.

Another flick of his mental trigger and he knew the exact velocity he would require.

It's impossible to know both the position and the velocity of a particle at any given time.

Imagine also looking at the car's speedometer as it travels, so that at every moment you know the velocity of the car.

"And now does my dear friend know the average molecular velocity of ordinary air?"

He knew the density of the atmosphere and the velocity and direction of the wind.

We would like to know the new velocity (v):

If you knew the velocity of a particle you didn't know its position.

It can therefore be used to map the bedrock depth knowing the S-wave velocity.

He explained that he knew the velocity of the bomb-fragments and could calculate their time of arrival in his head.