A force of 20 N acts on a surface of area [tex]$70 \, \text{cm}^2$[/tex]. Calculate the pressure exerted on the surface.

[tex]\text{Answer: } 2857 \, \text{Pa}[/tex]



Answer :

To find the pressure exerted on the surface when a force of 20 N acts on an area of [tex]\(70 \, \text{cm}^2\)[/tex], we can follow these steps:

1. Identify the Given Parameters:
- Force ([tex]\( F \)[/tex]) = 20 N
- Area ([tex]\( A \)[/tex]) = [tex]\(70 \, \text{cm}^2\)[/tex]

2. Convert the Area from [tex]\( \text{cm}^2 \)[/tex] to [tex]\( \text{m}^2 \)[/tex]:
Since the standard unit of area in the International System of Units (SI) is square meters ([tex]\( \text{m}^2 \)[/tex]), we need to convert [tex]\( 70 \, \text{cm}^2 \)[/tex] to [tex]\( \text{m}^2 \)[/tex]:
- There are [tex]\(100 \, \text{cm}\)[/tex] in [tex]\( 1 \, \text{m}\)[/tex], so [tex]\(1 \, \text{cm}^2 = (10^{-2} \, \text{m})^2 = 10^{-4} \, \text{m}^2 \)[/tex]
- Therefore, [tex]\( 70 \, \text{cm}^2 \)[/tex]:
[tex]\[ 70 \, \text{cm}^2 = 70 \times 10^{-4} \, \text{m}^2 = 0.007 \, \text{m}^2 \][/tex]

3. Calculate the Pressure:
We use the formula for pressure [tex]\( P \)[/tex], which is defined as the force divided by the area over which it is applied:
[tex]\[ P = \frac{F}{A} \][/tex]
Substituting the given values:
[tex]\[ P = \frac{20 \, \text{N}}{0.007 \, \text{m}^2} \][/tex]

4. Perform the Division:
[tex]\[ P = \frac{20}{0.007} \, \text{N/m}^2 = 2857.142857142857 \, \text{N/m}^2 \][/tex]

5. Round the Result (if necessary):
Often, results are rounded to a certain number of significant figures or decimal places. Here the pressure calculated is:
[tex]\[ P \approx 2857 \, \text{Pa} \][/tex]

Thus, the pressure exerted on the surface is approximately 2857 Pascals (Pa).