Question

Question:If the airstream from a hair dryer is directed over a table-tennis ball, the ball can be levitated. Explain.

Short answer

Partial vacuum will lift up the ball.

Step-by-step solution

Step 1: Bernoulli’s equation

The sum of the pressure, kinetic energy per unit volume, and gravitational potential energy per unit volume has the same value at all points along a streamline for an ideal fluid. This result is summarized in Bernoulli’s equation:

P+$\frac{1}{2}\rho v^2+\rho gh=cons\tan t$

Where

P = Pressure of fluid

V = Volume of fluid

$\rho =$Density of fluid

h = Height of fluid in pipe

Explain the reasoning

If the stream of air directed over the table tennis ball has very high velocity, it will create a low pressure over the table tennis ball, resulting in partial vacuum that will lift up the ball. This situation is based upon the application of Bernoulli’s principle.