help please: (1 Viewer)

[747captain]

Q: Why can't you measure the instantaneous velocity of an object with a stopwatch?

Has it got anything to do with:

• velocity changing constantly
• need to measure average velocity in a short segment
• etc.

???????????????????

Any help would be appreciated.

 

[alcalder]

Because velocity is two quantities - speed and direction.

You may be able to emasure speed but in an instant do you really know the direction. To measure the direction you need some time to pass in order to assess the direction and then you are not measuring the instantaneous speed.

(Sounds a bit like Heisenberg's Uncertainty Principle - the closer you know one quantity, the less likely the other HEE HEE).

So, yes, you need to find the average velocity of a period of time.

 

[747captain]

cool.

cheers for that alcalder

thanx so much:wave: