Question

the relationship of which physical quantities are described by second equation of motion ?​

Answer 1

The first equation of motion (Vf =Vi + at) deals with final velocity, initial velocity, acceleration and time. We can use the 1st equation of motion to find final velocity, initial velocity, acceleration and time.

The second equation of motion gives the displacement of an object under constant acceleration: x = x 0 + v 0 t + 1 2 a t 2 .

Answer 2

Again by definition, velocity is the first derivative of position with respect to time. Reverse this operation. Instead of differentiating position to find velocity, integrate velocity to find position. This gives us the position-time equation for constant acceleration, also known as the second equation of motion [2].