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