Question

A body traveling with uniform acceleration crosses two points A and B with velocities 20m/s and 30m/s respectively. The speed of the body at midpoint of A and B is

Answer 1

we can write  v₂ - u₂ = 2as = 900 - 400 = 500
∴ as = 250 --- (1)
at s/2 if speed is w: w₂ - u₂ = 2a(s/2)
∴ w₂ = u₂ + as = 400 + 250, using (1).
⇒ w = sqrt(650) =  25.5 m/s(approx)

Answer 2

Velocity is 25 because according to formula of acceleration (20 + 30)/2 = 25