A body is moving with a uniform acceleration covers 40m in the first 4 sec and 120m in next 4 sec.  Its initial velocity and acceleration are

A to B  :               $40=U\times 4+\frac{1}{2}\left(a\right)4^2$

                                             40   =   4U+8a -------------(1)

A to C :                 $40+120=U\times 8+\frac{1}{2}a\times 8^2$

                                            160  =  8U+32 a -----------(2) 

Solving (1) and (2)  ,  we get 

                                                U = 0  and a  =  5m/s²