Which statement about the Bernoulli principle is correct?

Which statement about the Bernoulli principle is correct?

• A. Increase in speed leads to an increase in pressure.
• B. Increase in speed leads to a decrease in pressure.
• C. Pressure remains constant as speed changes.
• D. It describes heat transfer in fluids.

Answer: (B)

In flows described by Bernoulli's principle, the sum of static pressure and the kinetic energy term remains constant along a streamline for steady, incompressible, frictionless flow. When height changes are negligible, this means P + ½ρv^2 is constant. So, if velocity increases, static pressure must decrease to keep the total the same. This is why the statement that an increase in speed leads to a decrease in pressure is the correct one. It also explains real-world effects like air moving faster over the top surface of a wing, where lower pressure helps generate lift. The other options don’t fit because increasing speed does not raise pressure, pressure does not stay constant as speed changes, and heat transfer is not described by Bernoulli’s principle.

In flows described by Bernoulli's principle, the sum of static pressure and the kinetic energy term remains constant along a streamline for steady, incompressible, frictionless flow. When height changes are negligible, this means P + ½ρv^2 is constant. So, if velocity increases, static pressure must decrease to keep the total the same. This is why the statement that an increase in speed leads to a decrease in pressure is the correct one. It also explains real-world effects like air moving faster over the top surface of a wing, where lower pressure helps generate lift. The other options don’t fit because increasing speed does not raise pressure, pressure does not stay constant as speed changes, and heat transfer is not described by Bernoulli’s principle.