physics force problem?

Question

A net force of 255 N accelerates a bike and rider at 2.20 m/s. what is the mass of the bike and rider?

I was thinking that since,

Force = mass x acceleration...

255N = 2.20m + 9.8m
255N = 12m
m = 21.25 kg

The answer is 16 kg and i'm lost as to how i'm not getting it.

Thanks

Answer 1

Your value of 2.20 m/s is a speed not and acceleration.

If it is supposed to be an acceleration then its units would be m/s/s.

If this is the case, then use your formula but don't include 9.8
The gravity constant does not play a role in this problem.

225N=2.20m/s/s x mass
solve for mass