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dreaburn85 · 2007-02-16 04:55:02

If you have a high acceleration, are you necessarily moving fast? Explain.

I think the answer is not that just because you have a high acceleration does not mean you are moving fast. You could be accelerating from 5m/s to 30m/s but that does not mean you are moving fast.

Do you think that is right?

arsashish · 2007-02-16 07:53:03

yes if the acceleration is high means that one is moving fast it is because..
acc=velocity/time.

the acceleration depends upon the two things....
so if the acc is high that means either velocity is high or time is less.
suppose velocity is high the it means you r moving fast...
now if time is less then also if we calculate in si or cgs system... it will show that velocity is high.
so in both the case velosity is high...
as a result this means that you ARE MOVING FAST.
IS IT CLEAR....?

Bishop · 2007-02-16 23:22:56

Hey drea - arsashish is talking out of his arse. Acceleration is really

a = (*CHANGE IN* velocity)/time = (delta_v)/t = (v2-v1)/t

You were right when you thought that high acceleration does not necesasrily mean high velocity. Acceleration is a *rate of change* of velocity. In fact, the acceleration can be astronomical while velocity is zero - all this means is that when you look again a second or so later, the velocity will be drastically different. For an example, particles in turbulent water can be accelerated very sharply, but they're only every moving a few m/s. So, yes, you were absolutely right.

Chris · 2007-02-19 23:15:56

Bishop is correct. However, the question is poorly formed.

To repeat Bishop:

$a = \frac{\Delta v}{\Delta t}$

What this means is that if you have a high rate of acceleration, then the velocity is changing quickly. So in a sense, a large acceleration means the rate at which the velocity changes is "fast". (This is not the same as the rate at which the displacement changes, or velocity, though they are related.)

At any given instant, you could be moving at close to the speed of light, however your acceleration could be zero.

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