A massless platform is kept on a light elastic spring as shown in fig. When a sand particle of mass $0.1 \mathrm{~kg}$ is dropped on the pan from a height of $0.24 \mathrm{~m},$ the particle strikes the pan and spring is compressed by $0.01 \mathrm{~m}$. From what height should the particle be dropped to cause a compression of $0.04 \mathrm{~m}$.