A block of 2 kg is suspended from the ceiling through a massless spring of spring constant k = 100 N/m. What is the elongation of the spring? If another 1 kg is added to the block, what would be the further elongation?

Given:

Mass of the block =

Spring constant =

∵ the block is in equilibrium the force due to spring must be equal to the weight of the block

Where x is the required extension,

∴

Now when more is added to the block, the weight of the block increases to

Using the equation of equilibrium,

Now as per the question we are asked to find further elongation,

∴ further elongation = elongation due to 3kg - elongation due to 2kg