Consider the two-dimensional velocity field given by V = (5+α₁x + b₁y) + (4+ α2x + b²y)), where a₁, b1, a2 and 6² are constants. Which one of the following conditions needs to be satisfied for the flow to be incompressible?

P-4 Please I need help with this question needed very clearly and step by step explanation and needed with clear handwriting please, will be really appreciated for your help

1. “The grain size of metal sheet influences its formability in two opposing ways. The yield strength of a metal increases as the grain size decreases. So, the formability of a component may decrease if the grain size gets too small. Larger grained metals have better formability, but the roughened surface that results from stretching metal with grain sizes that are too large is unacceptable for many applications. During a recrystallization anneal new grains form in the metal. The final grain size depends on the annealing temperature and annealing time.” As shown in the figure below (1"x1" area under a 50Xmagnification microscope), a cold-rolled metal has been annealed at 550 degrees C for one hour. Calculate the ASTM Grain Size Number for the following condition: image attached

Topics: Statics of Rigid Bodies, Equilibrium of Rigid Bodies, Equilibrium in Two Dimensions, etc.   I will rate you with “LIKE/UPVOTE," if it is COMPLETE STEP-BY-STEP SOLUTION.   If it is INCOMPLETE SOLUTION and there are SHORTCUTS OF SOLUTION, I will rate you with “DISLIKE/DOWNVOTE.”    THANK YOU FOR YOUR HELP.   PS: If you have answered this already, don’t answer it again; give chance to other experts to answer it. I want to verify if all of you will arrive in the same final answer; thats why I ask it multiple times. If you answer it again, i'll dislike all your entries/answers.