A company wishes to enhance its image by replacing oil-based plastics in its products by polymers that are based on natural materials. Use CES EduPack to find information on biopolymers. List the materials you find and state their significant applications. Which materials biopolymers are made from? Describe a plastic product on the market made from a bio-polymer, including which bio-polymer it is made from.
The wire of a hoist has a cross sectional area of 80 mm2. The hoist is used to lift a crate weighing 500 kg. What is the stress in the cable? The free length of the cable is 3 m. How much will it extend if it is made of steel (modulus 200 GPa)? How much will it extend if it is made of polypropylene, PP (modulus 1.2 GPa)? (assume purely elastic deformations).