Answer:160Ns
Explanation:
Mass(m)=4kg
Initial velocity(u)=18m/s
Final velocity(v)=22m/s
impulse=change in momentum
Impulse=m(v-u)
Since it's moving in opposite direction impulse=m(v-(-u))
Impulse=4(22-(-18))
Impulse=4(22+18)
Impulse=4x40
Impulse=160Ns