sir please explain question no 120 of unit and measurement.

Sir t1and t2 me relation nahi aa pa rha h mera

Sir what are the dimensions of electromotive force ? If I use formula v=E d for finding dimensional formula is it wrong?

H=1/2gt^2 --------1

H-40=1/2g (t-40)^2 -------2

Then find the value of 't'.

Sir 't' ki value nahi aa rhi please help sir

How to solve this question sir