Engineers are choosing a material for the blades of a new wind turbine. The blades are very long and must turn for about 20 years in wind and rain.
The table shows information about four materials.
| Material | Density / kg m−3\mathrm{kg\,m^{-3}}kgm−3 | Strength / MPa | Resistance to corrosion or rotting | Damage from repeated bending | Relative cost |
|---|---|---|---|---|---|
| glass-fibre composite | 1900 | 1000 | good | very little | 4 |
| aluminium alloy | 2700 | 300 | good | a lot | 3 |
| steel | 7800 | 500 | poor (rusts) | little | 1 |
| wood | 700 | 80 | poor (rots) | a lot | 1 |
Glass-fibre composite is made from glass fibres held in a polymer resin. Give one reason why the composite is less likely to snap than glass on its own.
One blade has a volume of 4.0 m3\mathrm{m^{3}}m3. Calculate the mass of a blade made from glass-fibre composite. Use the equation: mass=density×volume\text{mass} = \text{density} \times \text{volume}mass=density×volume
Calculate how much greater the mass of a steel blade of the same volume would be.
Evaluate the four materials for making the wind turbine blades. Use the information in the table.
36 exam-style questions on Edexcel GCSE Chemistry 10.5 Bulk and surface properties of matter including nanoparticles, covering 10.5.1 Nanoparticles: size, uses and risks and 10.5.2 Comparing and selecting materials. Each one has a worked solution and a mark scheme showing where the marks go.