Question

How long will it take a force of 2.5 N to bring a 0.25-kg object to rest if it was moving at 1.4 m/s?

Answer 1

F = ma

We also know that v = a*t
and we are looking for t

So now we can write a = F/m and fill in:

v = F*t/m or t = v*m / F

So finally:

t = 1.4 m/s * 0.25 kg / 2.5 N = 0.14 s