Answer eight questions in all; five questions from Part I and three questions from Part II. PART 1 [15 marks] Answer any five questions from this part. All questions carry equal marks.

5. Young's modulus is a measure of a material's stiffness or resistance to elastic deformation. A higher Young's modulus indicates a stiffer material.

• Aluminium is a metal with a crystalline structure and strong metallic bonds between its atoms. These bonds require a large amount of force (stress) to stretch or deform them, resulting in very little strain. This makes aluminium very stiff and gives it a high Young's modulus.
• Rubber, on the other hand, is an elastomer composed of long, coiled polymer chains held together by relatively weak intermolecular forces. These chains can easily uncoil and stretch under stress, leading to a large amount of strain for a given stress. This makes rubber highly elastic and gives it a much lower Young's modulus compared to aluminium.