Limitations of Bernoulli principle

The fluid particle velocity in the middle of a tube is utmost and reduces slowly in the direction of the tube because of friction. ...This equation is applicable to streamline the supply of a liquid. ...The external force of the liquid will affect the liquid flow.

Kinetic energy = 1/2mv^2. since the mass is constant we can form a ratio of it's kinetic energy at 60 divided by that at 30 to see ke(60)/ke(30) = +(60^2)/30^2). this may be said to 300% increase.