4) a drag racer starts from rest and accelerates at 10 m/s2 for the entire distance of 400 m (1/4
mile). what is the velocity of the race car at the end of the run?

Start with the givens and the unknown:
vi = 0
a = 10
d = 400
vf = ?

The kinematics equation incorporating these variables is:

vf^2 = vi^2 + 2ad
vf^2 = 0 + 2(10)(400)
vf^2 = 8000
vf = 89.4 m/s

It has more electrons than an neutral object