Make u the subject of formula, E = \(\frac{m}{2g}\)(v2 - u2)

The formula we want to solve for u is E = (m/2g)(v^2 - u^2).

To make u the subject of the formula, we need to isolate u on one side of the equation by performing the necessary algebraic operations.

First, we'll simplify the right side of the equation:

E = (m/2g)(v^2 - u^2)
2gE/m = v^2 - u^2    // Multiply both sides by 2g/m

Next, we'll isolate u^2 by adding it to both sides of the equation:

2gE/m + u^2 = v^2

Finally, we'll solve for u by taking the square root of both sides of the equation:

u = sqrt(v^2 - 2gE/m)

Therefore, the value of u as the subject of the formula is:

u = sqrt(v^2 - 2gE/m)

Option A is the correct answer.