2- Using the dimensional analysis, check the validity of the equation: x=21at2 where x : displacement, a : acceleration and t : time 3- Show that the expression v=v0+at is correct, where v and v0 : speeds, a : acceleration and t t time. 4- Test the validity of the equation: x=x0+v0t+21at2 where, x : displacement at time t,x0 : displacement at time t=0, v0 : velocity at time t=0 and a : acceleration due to gravity. 5- Using the dimensional analysis technique, find the relationship of the periodic time T of a simple pendulum if you know that the factors affecting are: mass of the bob (m), length (L) of the pendulum and the acceleration due to gravity (g)