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babybop09
Nov 6, 2011, 09:12 AM
transpose the formula v = u + at to make a the subject

Find the value of a in m/s2 when u = 18 m/s, v = 27 m/s, t = 10 s

jcaron2
Nov 6, 2011, 08:23 PM
You can figure this out, babybop. I'm assuming you missed a plus sign in there, so it should read

v=u+at

So how do you get a by itself? It's just simple algebra; you've probably been doing this for a couple years now. You can start by subtracting u from both sides. That gives you

v-u=at

Now there's just one more step to get a all alone. Can you handle the last step?

As for finding the value in m/s^2, that's just a matter of plugging in the numbers you're given.

berry9467
Aug 22, 2012, 03:38 AM
Please correct me if I get this wrong because I'm just starting to learn the basics of motion at school.
The formula I used is:
a=(v-u)/t
As for answering the question

a=(v-u)/t
a=(27-18)/10
a=-1ms^1
Which means it's decelerating at 1 meter every second.
I hope that helped, like I said before if I'm wrong then please correct me because I do not want to confuse others :)

ebaines
Aug 22, 2012, 06:00 AM
Berry9467: your answer is not quite right. Given v = final velocity = 27 m/s, u = initial velocity = 18 m/s, t = time = 10 s, and assuming acceleration is constant:


a = \frac {(v-u)} t = \frac {27 m/s - 18 m/s}{10 s} = 0.9 \frac m {s^2}


Note that the acceleration here is positive, and the correct units are meters per second squared.