11.A particle initially at rest starts moving with a uniform acceleration “a”. The ratio of the distances covered by it in first and the first 3s is
solution: a particle starts from rest (u)=0 the distance covered in first second (t)=1sec we have the formula S=ut+1/2at2 here ,u=0,t=1s,a=a S=0+1/2a(1)2 S1=1/2a the distance covered in 3sec S=ut+1/2at2 S=0+1/2a(3)2 S2=9/2a S1 :S2=1:9 the ratio of the distances covered by body is 1:9