The following data was obtained for a body of mass 1 kg dropped from a height of 5 metres:
Distance above ground Velocity
5 m 0 m/s
3.2 m 6 m/s
0 m 10 m/s
Show by calculations that the above data verifies the law of conservation of energy (Neglect air resistance). (g = 10 m/s2).
Total energy at 5m above ground = P.E. + K.E. = 50 J + 0 J = 50 J
Total energy at 3.2m above ground
= P. E. + K.E.
= 32 J + 18 J
= 50 J
Total energy at 0 m above ground = P. E. + K. E. = 0 J + 50 J = 50 J
The total energy (kinetic energy + potential energy) of the freely falling body at all the three positions during it falls remains the same.