A load of 50 N is suspended from a wire that has an area of cross-section of 1 mm² - AQA - A-Level Physics - Question 19 - 2019 - Paper 1

Stress is defined as the force per unit area. The formula for stress ( \sigma) is given by:

$\sigma = \frac{F}{A}$

Where:

• (F) = force in newtons (N)
• (A) = area in square meters (m²)

Given:

• Load, (F = 50 , \text{N})
• Area, (A = 1 , \text{mm}^2 = 1 \times 10^{-6} , \text{m}^2)

By substituting the values into the formula, we can calculate the stress:

$\sigma = \frac{50 \, \text{N}}{1 \times 10^{-6} \, \text{m}^2} = 50 \times 10^{6} \, \text{Pa} = 5 \times 10^{7} \, \text{Pa}$