Question

Pls answer with explanation​

Answer 1

Answer:

The correct answer is 4) $\sqrt\frac{u^{2}+v^{2} }{2}$

Explanation:

Let the length of the train is s, then by the third equation of motion,$v^{2}=u^{2}+2as$... (1)

Where v is final velocity after travelling a distance s with an acceleration a & u is initial velocity as per question

Let the velocity of the middle point of train at the same point is v', then

$v' ^{2} = u^{2} +2aX (\frac{s}{2}) ...(2)$

By equation (1) & (2), we get

$v'=\sqrt\frac{u^{2}+v^{2} }{2}$

Hope this helped you :D