Answer :
Final answer:
When blowing over the top of a sheet of paper, the air speed increases and the pressure above the paper decreases, causing the paper to rise due to the higher pressure below it. This demonstrates Bernoulli's principle, which describes the relationship between the speed and pressure of a fluid.
Explanation:
The subject of this question is Physics, specifically fluid dynamics related to Bernoulli's principle. The experiment described with the sheet of paper is a practical demonstration of how air speed and pressure are related. When you blow over the top of a sheet of paper, the paper will lift. This happens because the speed of the air on top of the paper increases, which, according to Bernoulli's principle, means that the pressure above the paper becomes less than the pressure below. The higher pressure below then pushes the paper up. This phenomenon is similar to the scenario given in the reference Figure 7.8.1, where the air passing between a car and a truck moves faster and thus creates a lower pressure region, which can result in the car and truck being pushed towards each other.
