Question

A massless platform is kept on a light elastic spring, as shown in the figure. When sand particles of 0.1 kg mass are dropped on the Pan from a height of 0.24 m, the particle strikes the Pan and the spring is compressed by 0.01 m. From what height should the particle be dropped to cause a compression of 0.04 m?

(a) 0.96 m

(b) 2.96 m

(c) 3.96 m

(d) 0.48 m

Answer 1

The correct option is (c) 3.96 m.

Explanation:

Let the particle be dropped from a height h and the spring be compressed by y According to conservation of mechanical energy,

Loss in PE of the particle = Gain in elastic potential energy of the spring

mg (h+y) = 1/2 ky²

Now, as the particle and spring remain same, hence