Speed of block at the end of one second after the start w.r.t.ground is(g=10m/s^2.
(We have to find this)
We have,
Acceleration of the elevator = 15 ( greater than )
Therefore, the body gets separated from the elevator. Thus body moves with the acceleration of 10
Initially block is at rest
therefore, u = 0
t = 0.2 sec
So, the speed of the block = v = u + at