My question is why is the energy balance like that Shouldnt

My question is: why is the energy balance like that? Shouldn\'t it be (m dot a)(h1)+(m dot v1)(h1) =(m dot a)(h2)+(m dot v 3)(h3)+(m dot w)(hw)+Qdot.

Why is the m dot v1 and m dot v3 not in the equation?

Solution

control volume means both sides volume is same thats why m dot v1 and m dot v3 canceled