Question

A 0.150 kg particle moves along an x axis according to x(t) = -13.00 + 2.00t + 3.50t2 - 2.50t3, with x in meters and t in seconds. In unit-vector notation, what is the net force acting on the particle at t = 3.45 s?

I tried solving using s=Vit + (.5)at^2 but I can't find the initial velocity of the particle. All you can find are the times and distances, you can find the average velocity from that but there is an acceleration so that's no good.

Answer 1

Really, no one?

Answer 2

all you do is take the derivative twice, to get the acceleration function, and then plug in 3.45 s. then use that acceleration to find f in F=ma