# Physics Force & Pressure Part 10 (Atmospheric Pressure) Class 8 VIII | Summary and Q&A

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September 12, 2015
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LearnoHub - Class 11, 12
Physics Force & Pressure Part 10 (Atmospheric Pressure) Class 8 VIII

## TL;DR

Atmospheric pressure is the force exerted by the Earth's atmosphere, and it affects various objects and phenomena, such as rubber suckers and drinking straws.

## Key Insights

• ❓ The Earth's atmosphere is composed of different layers and extends several hundred kilometers above the surface.
• 👱 Atmospheric pressure is the force exerted by the weight of the air on a unit area.
• 🍓 Objects like rubber suckers and drinking straws demonstrate the effects of atmospheric pressure.
• 🤢 Atmospheric pressure changes with height, but at sea level, it is approximately 1.01 × 10^5 Pascals or 1 atmosphere.
• ❓ Atmospheric pressure is measured using instruments like a mercury barometer.
• 🇦🇪 The SI unit of pressure is Pascal (Pa), and another unit commonly used is atmosphere (atm).
• 🍓 Atmospheric pressure affects various phenomena, such as the movement of fluids through straws.

## Transcript

hello friends this video on force and pressure part 10 is brought to you by exam for calm no more fear from exam so now that we have spoken so much about pressure we let us talk about an important concept that is atmospheric pressure so pressure is also exerted by atmosphere so the pressure exerted by atmosphere around as x1 atmospheric pressure no... Read More

### Q: What is atmospheric pressure?

Atmospheric pressure is the force exerted by the Earth's atmosphere on objects and surfaces due to the weight of the air above them.

### Q: Why don't we feel the atmospheric pressure on our bodies?

We don't feel the atmospheric pressure because it is balanced by the pressure exerted by the gases within our bodies.

### Q: How does atmospheric pressure affect rubber suckers?

Atmospheric pressure helps rubber suckers stick to smooth surfaces by pressing them securely against the surface due to the difference in pressure inside and outside the sucker.

### Q: Why does liquid rise in a drinking straw when we suck on it?

When we suck on a drinking straw, the decrease in pressure inside the straw creates a difference between the internal and external atmospheric pressure, causing the liquid to rise through the straw.

## Summary & Key Takeaways

• Atmospheric pressure is the pressure exerted by the Earth's atmosphere on objects and surfaces.

• The atmosphere is composed of different layers, and it extends several hundred kilometers above the Earth's surface.

• The weight of the air on a unit area defines atmospheric pressure, and it can be observed in everyday examples like rubber suckers and drinking straws.