EIT - Engineer In Training Fluid Mechanics Questions and Answers

Question 1

Water flows through a horizontal pipe that transitions from a diameter of 10 cm to a diameter of 5 cm.
If the velocity in the 10 cm section is 1.5 m/s, what is the approximate velocity in the 5 cm section, assuming incompressible flow?

Accepted Answer

6.0 m/s

Answer

0.75 m/s

Answer

3.0 m/s

Answer

0.375 m/s

Question 2

A 0.5 m³ block of wood with a specific gravity of 0.7 is held fully submerged in freshwater (density ≈ 1000 kg/m³). What is the magnitude of the buoyant force acting on the block? (Use g = 9.81 m/s²)

Accepted Answer

4905 N

Answer

3434 N

Answer

6867 N

Answer

500 N

Question 3

In fluid mechanics, the Reynolds number (Re) is a dimensionless quantity used to predict flow patterns. Which of the following statements is most accurate regarding flow in a pipe?

Accepted Answer

It represents the ratio of inertial forces to viscous forces.

Answer

It is the ratio of viscous forces to inertial forces.

Answer

A Reynolds number below 2300 typically indicates turbulent flow.

Answer

It is directly proportional to the fluid's kinematic viscosity.

Question 4

Water flows from a large-diameter pipe into a smaller-diameter pipe at the same elevation. Assuming no frictional losses, which of the following occurs?

Accepted Answer

The fluid velocity increases and the pressure decreases.

Answer

Both the fluid velocity and pressure increase.

Answer

The fluid velocity decreases and the pressure increases.

Answer

Both the fluid velocity and pressure decrease.

Question 5

A vertical rectangular gate in a dam is 2 meters wide and 3 meters high, and its top edge is 4 meters below the water surface. What is the total hydrostatic force acting on the gate? (Use ρ_water = 1000 kg/m³, g = 9.81 m/s²)

Accepted Answer

264.9 kN

Answer

176.6 kN

Answer

235.4 kN

Answer

323.7 kN

Question 6

A U-tube manometer filled with mercury (SG = 13.6) is used to measure the gauge pressure of a gas. The mercury level on the side open to the atmosphere is 15 cm higher than the level on the side connected to the gas. What is the gauge pressure of the gas? (Use ρ_water = 1000 kg/m³, g = 9.81 m/s²)

Accepted Answer

20.0 kPa

Answer

14.7 kPa

Answer

1.47 kPa

Answer

133.4 kPa