[" Two billiard balls each of mass "0.05kg" moving "],[" in opposite directions with speed "6ms^(-1)" collide "],[" and rebound with the same speed.The impulse "],[" imparted to each ball due to the other will be "],[[" (1) "-0.30kgms^(-1)," (2) "+0.30kgms^(-1)],[" (3) "-0.60kgms^(-1)," (4) "+0.60kgms^(-1)]]