Forces: Upthrust and Atmospheric Pressure

Upthrust

When an object is immersed in a fluid (either liquid or gas), the fluid exerts an upward force on the object. This is known as upthrust or buoyancy.
Upthrust is caused by a difference in pressure at different depths in the fluid. At greater depths, fluid pressure is higher.
The force of upthrust depends on two primary factors: the volume of the fluid displaced by the object and the density of the fluid. An object will float if the upthrust is equal to the weight of the object.
According to Archimedes’ Principle, the upthrust on an object immersed in a fluid is equal to the weight of the fluid that has been displaced by the object.

Atmospheric pressure refers to the force exerted on a surface due to the weight of the atmosphere above it. It is also referred to as air pressure or barometric pressure.
Atmospheric pressure decreases with increasing altitude. This is because as you move upwards, there is less atmosphere (and thus less air weight) above you.
Pressure in fluids, including the atmosphere, can be calculated using the formula: pressure (Pa or N/m²) = force (N) / area (m²)
High atmospheric pressure generally correlates to calm, fair weather, while low atmospheric pressure can indicate stormy weather.
Humans are adapted to the atmospheric pressure at sea level, and changes in atmospheric pressure, such as when climbing a mountain or flying, can have physiological effects.
Measuring atmospheric pressure is crucial in various fields such as meteorology, aviation, and even in predicting natural disasters like hurricanes.