At one point in a pipeline, the water's speed is 3.57 m/s and the gauge pressure is 68.7 kPa. Find the gauge pressure at a second point in the line, 18.5 m lower than the first, if the pipe diameter at the second point is twice that at the first. Remember that the density of water is 1000 kg/m3. Please give your answer in units of kPa.

The  pressure at point 2 is

Explanation:

From the question we are told that

   The speed at point 1  is  

   The  gauge pressure at point 1  is  

    The density of water is  

Let the  height at point 1 be   then the height at point two will be

Let the  diameter at point 1 be   then the diameter at point two will be

Now the continuity equation is mathematically represented as  

Here  are the area at point 1 and 2

    Now given that the are is directly proportional to the square of the diameter [i.e ]

   which can represent as

=>        

where c is a constant

  so      

=>          

=>        

Now from the continuity equation

=>    

=>    

Generally the Bernoulli equation is mathematically represented as

So  

=>    

substituting values

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.