If immediately before hitting the earth the kinetic energy of a mass of 2 {kg} is 400 {J}. At what height was it dropped? ( {g}=10 {m} \/ {s}^{2}, friction is negligible)

Maharashtra State PSC Model Paper 4

Question : 73 of 100

Marks: +1, -0

If immediately before hitting the earth the kinetic energy of a mass of

2 {kg}

400 {J}

. At what height was it dropped?

( {g}=10

{m} \/ {s}^{2},

friction is negligible)

Solution:

The correct answer is 20 m.

Important Point

Concept:
- When the body is released from a height then all the potential energy will be converted to kinetic energy. P.E. $+0= {K} . {E} ⋅+0$
  ${P} . {E} .= {mgh}=400 {J}$
  Here, ${m}=2 {kg}$ and ${g}=10 {m} {/} {s}^{2}$
  ${mgh}=400$
  $2 * 10 * {h}=400$
  ${h}=20 {m}$

Go to Question:

Prev Question

Next Question