Applications of elastic behaviour of materials
Stress, strain and Hooke's law · Physics
Study notes
Example: Find how much a steel spring stretches when a 2 kg weight is hung from it. Step 1: Convert weight to force. Force (F) = mass (m) × gravity (g). Here, m = 2 kg and g ≈ 9.8 m/s². F = 2 × 9.8 = 19.6 N. Step 2: Know the spring constant (k). Suppose the spring constant is 50 N/m. Step 3: Use Hooke’s law: F = k × x, where x is the extension. Step 4: Solve for x: x = F / k = 19.6 N / 50 N/m = 0.392 m. Answer: The spring stretches about 0.39 meters (39.2 cm) when the 2‑kg weight is attached.