Fluid — Science definition
A liquid or gas that flows.
Where it is taught
- Pressure & Buoyant Forces — Forces, Physical Science: Matter, Forces & Energy, Grade 8
In use
Within a stationary liquid, pressure increases with depth because more fluid lies above.
Pressure & Buoyant Forces
Questions using fluid
Problem 1
Answer and explanation
Using force = pressure × area, the piston forces are 20 N and 80 N. In an ideal hydraulic arrangement, the larger force acts through a smaller distance while displaced volumes balance, so energy is not created. The displaced-fluid model gives an 8 N buoyant force; floating equilibrium also requires the object’s weight to be balanced.
Using force = pressure × area, the piston forces are 20 N and 80 N. In an ideal hydraulic arrangement, the larger force acts through a smaller distance while displaced volumes balance, so energy is not created. The displaced-fluid model gives an 8 N buoyant force; floating equilibrium also requires the object’s weight to be balanced.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.