When two steel balls are struck together with paper between them, the collision generates enough heat to scorch and burn the paper.

1. Obtain two solid steel balls.
2. Strike the steel balls together with the paper in between.
3. Repeat the collision a few times until a burning smell is noticeable.
4. Observe the appearance of brown or black scorch marks and small holes in the paper.

Burning paper with steel ball-bearings - Steve Mould:

📄 Two balls colliding can create heat and burn paper - Utah Physics: https://web.physics.utah.edu/~sps/demo/node21.html#:~:text=Hit%20the%20two%20steel%20balls,and%20holes%20in%20the%20paper.

• Use different thicknesses of paper to test how easily it scorches.
• Try balls of different materials (e.g., brass, aluminum) to compare heat effects.
• Test whether repeated lighter collisions produce the same effect as fewer strong impacts.

• Keep fingers clear of the impact area to avoid injury.

• What form of energy conversion is taking place in this demonstration?
• Why does the paper burn but not catch fire completely?
• How does the law of conservation of energy explain what happens during the collision?
• Would elastic collisions generate the same amount of heat? Why or why not?
• What factors influence how much heat is generated at the point of impact?