Average acceleration

Identity · 2009-07-15 00:50:40

A particle moves in a line with velocity

given by . The object starts from the origin. Find the average acceleration over the third second.

The answer is

but no matter what I try I can't seem to get it.

If t=0 to t=1 is the first second, then t = 2 to t = 3 should be the third second, but I've found v(3)-v(2) and it's still not right!

bobbym · 2009-07-15 01:58:17

Hi Identity;

Use mathsys method below:

Last edited by bobbym (2009-07-15 06:50:44)

mathsyperson · 2009-07-15 02:11:03

Your way should work too, Identity.
Technically, it's:

But that's the same as what you had, so you shouldn't be getting a different answer.

Identity · 2009-07-15 22:36:51

Thanks, maybe the book was wrong

mathsyperson · 2009-07-16 00:07:27

I agree with the book's answer.

v(3) - v(2) = 3/10 - 2/5 = -0.1

bobbym · 2009-07-16 03:01:11

Hi identity;

I do too.

Average acceleration = Δv/Δt = -.01 m/s^2

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