Answer
n1.) Use J=Δp    so……
nJ=10N.s(E)=Δp=10kg.m/s(E)
nand since original p was 0kg.m/s and Δp=10kg.m/s(E),
n new p=10kg.m/s(E)
nthen use….. p=mv     so……..
n10kg.m/s(E)=5.0kg x v    so….
n
n v=2m/s(E)