Question

A 5.00 kilogram mass is traveling at 100 meters per second. Determine the speed of the mass after an impulse of 30 Newton * seconds is applied.

Answer 1

Given: Mass m = 5.0 Kg;   Initial Velocity Vi = 100 m/s

            Impulse Ft = 30 N.s

Required: Final Velocity = ?

Formula: Ft = m(Vf -Vi)

               Vf = Vi + Ft/m

               Vf = 100 m/s + 30 N.s/5 Kg

               Vf = 100 m/s + 6 m/s

               Vf = 106 m/s

             

Answer 2

Impulse is the change in momentum, J. It is measured in the same unit as momentum, kg•m/s or N•s
 The formula for impulse is
 J = ∆p = pf - pi
 30Ns = pf - pi
 pi = m*vi
 pi = (5kg)(100m/s)
 pi = 500kg-m/s
 pf - 500kg-m/s = 30Ns
 pf = 530kg-m/s
 pf = m*vf
 v f = pf /m
 v f = (530kg-m/s)/(5kg)
 v f = 106m/s (speed of the mass after an impulse)