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A massless platform is kept on a light elastic spring as shown in the fig. When sand particle of 0.1 kg mass is 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? |
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Answer» Here, m= 0.1 kg h = 0.24 m x = 0.01 m When particle is dropped from a height h and spring is compressed by x, then loss in P.E. of particle = mg(h + x), while gain in elastic potential energy of spring will be, 1/2 kx2 Hence, mg(h + x) = 1/2 kx2 Similarly, mg(h' × x') = 1/2 kx12 Dividing, we get {h + x}/{h' + x'} = (x/x')2 ⇒ {0.24 + 0.01}/{h' + 0.04} = (0.01/0.04)2 On solving, we get, h' = 3.96 m |
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