The answer to the question is that before the big bang, the universe was much hotter and more dense than it is now. Letter B.
It is because after the big bag occurred, the universe became cooler and less dense.
a. - does not correspond in the answer because the universe became less dense after the big bang.
c - the universe became cool and less dense after the big bang so being cool and less dense does not correspond to the question.
d - cooler does not answer the question because it only became cooler after the big bang.
You're supposed to divide the mass by the volume, which is going to equal to 5
As here it is given that
x = 150 m
a= 2 m/s^2
now initial speed of the plane must be zero as it start from rest
now we will use kinematics



so its final speed is maximum 24.5 m/s
so it will not reach to desired speed at the end of runway