Answer:
.25 m/s
Explanation:
We shall use the law of conservation of momentum . We do not use law of conservation of mechanical energy because in such cases there is loss of energy.
Momentum = mass x velocity
Initial momentum of arrow and block
= .15 x 30 +0 = 4.5 J
If final velocity of block be V
Total final momentum of both arrow and block
= .15 x 25 + 3 V
= 3.75 +3V
So
3.75 + 3 V = 4.5
V = .25 m/s
