Fluid Mechanics and Hydraulics Flashcards
7 cards from real Bennett Mechanical Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fluid Mechanics and Hydraulics flashcards as text
Which statement best describes Bernoulli's principle?
Answer: Faster-moving fluid exerts lower pressure
Bernoulli's principle states that as fluid velocity increases, its pressure decreases.
When water flows through a pipe that narrows, the water's speed:
Answer: Increases
By continuity, the same volume passing through a smaller area must move faster.
As water flows through a narrowing section of pipe, the pressure in that narrow section:
Answer: Decreases
Faster flow in the narrow section lowers the pressure per Bernoulli's principle.
The continuity equation for fluids states that, for a given pipe, the product of which two quantities stays constant?
Answer: Cross-sectional area and velocity
Area × velocity is constant, so flow rate is conserved along the pipe.
Why does the roof of a house sometimes lift off during high winds?
Answer: Fast wind over the roof lowers pressure above it
Fast air over the roof creates lower pressure above, so higher inside pressure pushes it up.
A garden hose sprays water farther when you cover part of the opening with your thumb because:
Answer: Reducing the area increases the exit velocity
Shrinking the opening forces the same flow through a smaller area, raising exit speed.
An atomizer or spray bottle works because air moving quickly past a tube:
Answer: Creates low pressure that draws liquid up
Fast-moving air lowers pressure at the tube top, so atmospheric pressure pushes liquid up.