A flat plate of 4m length is kept parallel to air flowing at 5 m/s at 15°C .Assuming the density of air to be 1.2kg/m3 and dynamic viscosity to be 1.76 × 10-5 kg / m-s, and knowing that the flow becomes turbulent when Reynolds number exceeds 5 × 105 , the flow will become turbulent at
1
1.25 m
2
1.47 m
3
1.52 m
4
1.74 m