Question

If a 1350 kg minivan hits a barrier with a force of 2500 n and stops in 2.8 sec, how fast must the minivan have been traveling?

Answer 1

v = Vi + a t
stops so
0 = Vi + a (2.8)
and
-2500 = m a = 1350 a
a = -1.85 m/s^2

0 = Vi - 1.85*2.8
Vi = 5.19 m/s