Question

Length of a wire increases by 1mm under 1kg weight.What will be the increase in the length of wire under 2kg.What about increase in length under 100kg?

Answer 1

This is a question on spring constant.

k = F/e

k = spring constant

F = force = mg

e = Extension.

Take g = 10

F = 1 × 10 = 10 N

k = 10/1 = 10

Now for 2kg :

F = 2 × 10 = 20 N

e = F/k

hence :

20/10 = 2mm

for 100 Kg:

F = 100 × 10 = 1000N

e = 1000/10 = 100 mm