Question

Please give answer with steps...

Answer 1

here
u1=0m/s (at rest)
u2=0m/s(at rest)
m1=2kg
m2=1kg
after exploding
v1=3m/s
v2=?

now according to law of conservation of momentum

m1u1 +m2u2 =m1v1 +m2v2
therefore
1*0 +2*0 = 2*3 + 1* v2
0=6 + v2
v2= -6m/s
where (-) indicates in opposite direction