posted by vinay .
the velocity acquired by a body moving with uniform acceleration is 12 m/s2 in 2 secs.and 18 m/s2 in 4 sec. find the initial velocity of the body?
Hmmm. I am wondering if you meant 12m/s and 18m/s. I will assume so.
subtract first from second equation
6=2a a=3 m/s^2
12=Vi+2*3 solve for vi