Question

When the cutting edge of a knife is put against a fast rotating stone t o sharpen it, sparks are seen to fly. Explain the reason. NCERT Class VIII Science - Exemplar Problems Chapter 12. Friction

Answer 1

Ans: Friction generates heat. When the cutting edge of a knife comes in contact with a fast-
rotating stone, heat is produced due to friction between the grinding stone and the cutting
edge of the knife. As the friction is very large, a large amount of heat is produced and sparks
are seen flying while sharpening the cutting edge of the knife.

Answer 2

Answer:

Friction gernates heat when two objects come connect.