Question

Two light balls are suspended as shown in figure. When a stream of air passes through the space between them, the distance between the balls will ______.

Options

• remain same

• increase

• may increase or decrease, depending on speed of air

• decrease

Answer 1

Two light balls are suspended as shown in figure. When a stream of air passes through the space between them, the distance between the balls will decrease.

Explanation:

When a stream of air passes between the balls, the pressure between them decreases when compared to the atmospheric pressure on either side. The pressure energy should be constant, according to Bernoulli's theorem, and is compensated by the movement of the balls toward each other. As a result, the gap between the balls will shrink.