Understanding Pressure

Pressure is defined as force distributed over an area:

* Pressure (P) = Force (F) / Area (A)

Calculations

1. Area: The thumbtack's head is circular. The area of a circle is calculated using the formula:

* Area (A) = π * radius²

* A = π * (5 mm)² = 25π mm²

* Convert millimeters to meters: A = 25π * (10⁻³ m)² = 25π * 10⁻⁶ m²

2. Pressure:

* P = F / A

* P = 25 N / (25π * 10⁻⁶ m²)

* P ≈ 318,309.89 Pa (Pascals)

Result

The pressure exerted by your thumb on the thumbtack is approximately 318,309.89 Pascals.