Question

Where we should use third equation of motion

Answer 1

So v square minus u square is equal to twice as. This is our third equation of motion. So the total equation of motion is the relation between acceleration, initial velocity, final velocity and displacement. Given any three of these terms, we can use the third equation of motion to find the fourth one.

Answer 2

The third Equation of motion is....

v² =u²-2as

Here , final velocity [v] , initial velocity [u] ,acceleration [a] and  displacement [s] are given .

So any three are given and we have to find fourth ,or two are given and we have to find the ratio of other two , we should use this equation