What is atmospheric pressure? what is it caused by Physics Q&A (2024)

FAQs

What is atmospheric pressure? what is it caused by Physics Q&A? ›

That pressure is known as atmospheric pressure, also known as air pressure. It is the force exerted by the air above a surface as gravity pulls it to Earth. A barometer is commonly used to measure atmospheric pressure.

The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer.

Atmospheric pressure is caused by the weight of air molecules above the atmosphere. The layer of air exerts a force on the surface of the earth. The force per unit area, by the atmosphere, on the surface of any object on the earth is called atmospheric pressure. At the sea level this pressure is equal to 101325 Nm-2.

What is the cause of atmospheric pressure? The weight of air.

The basic cause of atmospheric refraction is variation in optical density of different layer's of earth atmosphere. The sunlight passes through various regions of earth's atmosphere, which have varied optical densities.

Areas of high and low pressure are caused by ascending and descending air. As air warms it ascends, leading to low pressure at the surface. As air cools it descends, leading to high pressure at the surface.

A low pressure system has lower pressure at its center than the areas around it. Winds blow towards the low pressure, and the air rises in the atmosphere where they meet. As the air rises, the water vapor within it condenses, forming clouds and often precipitation.

Atmospheric pressure varies due to altitude and temperature, among other factors. In general, an increase in altitude will cause a decrease in pressure. And an increase in temperature will cause an increase in pressure, as long as other variables (like volume) remain constant.

The best explanation for the cause of atmospheric pressure is: weight of the air above.

As air leaves the high-pressure area, the remaining air sinks slowly downward to take its place. That makes clouds and precipitation scarce, because clouds depend on rising air for condensation. High-pressure areas usually are areas of fair, settled weather.

Why do planets not twinkle? ›

Planets do not twinkle because they appear larger in size than the stars as they are relatively closer to earth. Planets can be considered as a collection of a large number of point-size sources of light.

Atmospheric refraction near the ground produces mirages. Such refraction can also raise or lower, or stretch or shorten, the images of distant objects without involving mirages. Turbulent air can make distant objects appear to twinkle or shimmer. The term also applies to the refraction of sound.

Air molecules colliding with a surface cause atmospheric pressure.

“The most commonly reported result of changes in barometric pressure on our health is associated with headaches and migraines,” says Dr. Joseph Aquilina, chief medical officer of SharpCare Medical Group. “The likelihood of a headache is also increased if there is already any congestion or blockage in the sinuses.”

At standard sea level, the barometric pressure equals 760 mm (29.92 inches) of mercury. A rise in barometric pressure is generally considered an improvement in the weather, while a fall in barometric pressure may mean worsening weather.

Barometric pressure range

A barometric reading over 30.20 inHg is generally considered high, and high pressure is associated with clear skies and calm weather. A barometric reading below 29.80 inHg is generally considered low, and low pressure is associated with warm air and rainstorms.

Atmospheric pressure, barometric pressure, and air pressure all refer to the same thing: the weight of the atmosphere at any location, generated by the downward force of gravity. Pressure decreases with increasing elevation because there is less air above you.