18 flashcards · Shared on 19 August 2026 by AtomAI Library
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Which equation defines pressure on a surface?
pressure = force ÷ area
Which equation defines pressure on a surface?
pressure = force ÷ area
Why does a sharp knife produce more pressure than a blunt knife when the same force is applied?
The sharp knife has a smaller contact area
According to Archimedes' principle, the upthrust on an immersed object equals what?
The weight of the fluid displaced
An object floats at rest on a liquid. Which statement about the vertical forces is correct?
Its weight equals the upthrust
How does a hydraulic system multiply force?
It applies the same pressure to a larger output piston area
Which expression gives the pressure increase at depth h in a liquid of density ρ?
ρgh
For a fixed mass of gas at constant temperature, what happens to its pressure when its volume decreases?
It increases because particles collide with the walls more frequently
Why does atmospheric pressure generally decrease with increasing altitude?
There is less air above exerting weight
What is upthrust on an object in a fluid?
The upward resultant force exerted by the fluid
Why is there usually an upward resultant force on an object submerged in a liquid?
Pressure on the bottom is greater than pressure on the top
How does pressure in a liquid change as depth increases?
It increases because of the weight of liquid above
Two points are at the same depth in the same stationary liquid. How do their pressures compare?
The pressure is the same at both points
What causes gas pressure inside a container?
Gas particles colliding with the container walls
What usually happens when a solid object is released while fully submerged in a liquid denser than the object's average density?
It rises because the upthrust exceeds its weight
What is the density of a substance?
Its mass per unit volume
What is the SI unit of pressure?
pascal
A force of 200 N acts uniformly over an area of 0.50 m². What pressure is produced?
400 Pa
In which direction does fluid pressure act on a surface?
Perpendicular to the surface