Answer:
The time is [tex]t = 6.62 \ s[/tex]
Explanation:
From the question we are told that
The height of the platform where the ball was dropped from is s = 215 m
The acceleration due to gravity is [tex]g = 9.8 \ m/s^2[/tex]
Generally from kinematic equations
[tex]s = ut + \frac{1}{2} gt^2[/tex]
Here u is the initial velocity of the ball and the value is u = 0 m/s given that the ball was at rest before it was dropped
So
[tex]21 5 = 0 * t + \frac{1}{2} * 9.8t^2[/tex]
=> [tex]21 5 = 4.9t^2[/tex]
=> [tex]t^2 = \frac{215}{4.9}[/tex]
=> [tex]t = 6.62 \ s[/tex]
