"A hair dryer can be used to create a stream of air. Is the air pressure in the center of the stream greater than, less than, or equal to the air pressure at some distance from the center of the stream?Explain.

greater than

Explanation:

Solution:

- We can use the Bernoulli's equation which is the sum of Pressure energy, kinetic energy / unit volume and potential energy/ unit volume must always remains constant at two points. As follows:

- Where, Psi : Static pressure at any point

              Vi : Velocity at any point

              hi : Elevation head at any point

- Assuming the velocity at center of stream and point 2 is constant. The center of stream is taken as datum hence, h1 = 0. we get:

Hence,

- The air pressure at center is higher than air pressure at a distance h from center of stream.

force tends to be low and long diustance masses are high