Topic 11 - Force and Pressure Flashcards
What is upthrust?
The upward force that acts on a body partly or completely submerged in a fluid.
What is a Pascal?
A unit of pressure equivalent to one Newton per metre squared.
How does liquid pressure change the deeper you go?
The deeper you go the higher the pressure since the volume of water exerting force from above you is greater.
What is the equation for Pressure?
Pressure = Force/Area
What is the equation for pressure in a liquid?
Pressure = density x gravitational field strength x depth (height) under the surface
What is pressure equal?
The force per unit of area.
How does atmospheric pressure increase with altitude?
Atmospheric pressure decreases since there are less air particles above you at higher altitudes above sea level.
How does water pressure change with depth?
The deeper an object is under water, the higher the pressure since there is a higher volume of water above it and therefore acting on it.
What is the equation for density?
Density = mass/volume
If an object has a lower density than water, will it float or sink?
It will float.
What causes upthrust?
The difference in pressure between the liquid and the object in the liquid causes upthrust.
What happens to pressure as you go deeper underwater?
It increases with depth as there is more water above you
Apart from depth, what else affects pressure in a liquid?
Density
What causes atmospheric pressure?
Molecules colliding with surfaces, exerting a force on the object.
How far does Earth’s atmospheric pressure extend?
Over 100km into space.
