A block of mass m is suspended from the ceilling using a string C. Another piece of string D is fitted to the other end of block. When the string D is pulled suddenly, it snaps . But when D is pulled slowly. The string C snaps. Explain.

A block of mass m is suspended from the ceilling using a string C. Ano

1.	A block of mass m is suspended from the ceilling using a string C. Another piece of string D is fitted to the other end of block. When the string D is pulled suddenly, it snaps . But when D is pulled slowly. The string C snaps. Explain.
Answer» Solution :Application of a sudden pull (T) on string D does not disturb the block due to its inertia. Extension of thestring C is negligible as the block PRACTICALLY REMAINS at the same place. In this case only the weight W acts on C and the string does not snap. On the other string does not snap. on the other hand, the force T may be sufficient for D to snap. But when string D is SLOWLY pulled, the applied force acts on the WHOLE SYSTEM. So, the tension T. on the string D becomes less than the tensionT. + W on C as the block also starts coming down. the tension, being higher, causes the string C to snap.