Question

A body travelling with uniform acceleration crosses two points A and B with velocities 20ms−1 and 30ms−1 respectively . The speed of the body at the mid-point of A and B is

Answer 1

Because body is moving with uniform acceleration so it's velocity will be 25ms-1 at the mid-point of A and B by taking average.

If acceleration is not uniform then velocity can be calculated with the help of slope of the graph, this velocity is called instantaneous velocity.