question_answer 42)

  A body is falling from a height h, After it has fallen a height  , it will possess (a) only potential energy (b) only kinetic energy (c) half potential and half kinetic energy (d) more kinetic and less potential energy

Answer:

  (c) As we know that when a body is at height h, it has total energy = KE+ PE and at height 'h', velocity of body is zero. (m) So,          KE = 0 and PE = mgh                       So,          total energy = mgh + 0 = mgh                          Now, at height     Its,                          Now at height And             ?(i)     Where, velocity can be determined by equation of motion       ( All v, g, h are in same direction) [As u = 0 at highest point] So,                    So,                                                                                                                     ...(ii) So, from Eqs. (i) and (ii) body at  possesses half potential energy and half kinetic energy.