| Difficulty | Secondary School | High school/other |
| ★ | Basic | Easy |
| ★★ | Demanding | Basic |
| ★★★ | Demanding | |
| ★★★★ | Difficult | |
| ★★★★★ | Very difficult |
Determine the modulus of elasticity of the solid metal bar. What metal could the bar be made of? (Note: Video contains audio)
Answer: $192\cdot{10^9}\frac{N}{m^2}$