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Ch.10 - Gases
Chapter 10, Problem 15b

A person weighing 75 kg is standing on a threelegged stool. The stool momentarily tilts so that the entire weight is on one foot. If the contact area of each foot is 5.0 cm2, calculate the pressure exerted on the underlying surface in (b) atmospheres

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Pressure

Pressure is defined as the force exerted per unit area. In this context, it is calculated by dividing the weight of the person by the contact area of the stool's foot that is in contact with the ground. The formula for pressure (P) is P = F/A, where F is the force (weight) and A is the area.
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Units of Pressure

Pressure can be expressed in various units, including pascals (Pa), atmospheres (atm), and millimeters of mercury (mmHg). To convert pressure from pascals to atmospheres, one can use the conversion factor: 1 atm = 101,325 Pa. Understanding these units is essential for accurately reporting the pressure exerted.
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Weight and Force

Weight is the force exerted by gravity on an object and is calculated as the product of mass and gravitational acceleration (W = mg). In this scenario, the person's weight (75 kg) contributes to the total force acting on the stool, which is crucial for determining the pressure on the surface below.
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