Question

A racing car has an acceleration of 4m/s^2. What distance will it cover in 20 seconds after start?

Answer 1

we will use the formula:-
s=ut+1/2 at2
s=0x20+1/2x4x20x20
s=o+1/2x4x400
s=800m

i hope it is correct 

Answer 2

here
      u=0
      a=4 m/s^2
      t=20 sec
by using 
             s = ut+1/2at^2
             s = 0+1/2×4m/s²×20 s
                =40 m