A body of mass 5kg initially at rest is subjected to a force of 20 N. Find the kinetic energy acquired by the body at the end of 10 seconds.(g=10 m/s

F=ma
a=20/5=4m/s²
s=ut+1/2at²           
s=1/2at²
s=1/2*4*10*10=200m
we know ,
work done =change in kinetic energy
therefore
Fs=1/2m(v²-u²)                                                                  
u=0 object is at rest
20*20=1/2*5*v²
              therefore
v²=160
v=40m/s
g has got no use