Originally Posted by

**edwardkiely** So this is what I did

so the force varies over time and we not one of the conditions. so I said F=Kt where k is a constant which we do not know and t is time. so the question says the force is 12N when t is20

so 12=20k 3/5 =k so then using F=ma 3/5 *t =6a a=t/10

I then let dv/dt and I let the upper limits be t and v and I rearranged to get t=√(20v)

so i then let t/10 = v dv/ds and I subbed in t=√(20v) and I integrated this and I got a useless expression. I thought I did every thing right and I can not see where I went wrong