Height of the platform = 100 feet
1 feet = 0.3048 m
100 feet = 30.48 m
Acceleration due to gravity (g) = 9.8 m/s^2
Let the time taken be t
Initial velocity of the object (u) = 0 m/s
Using the seconds equation of motion:
[tex]s = ut + \frac{1}{2}at^2[/tex]
[tex]30.48 = 0 + \frac{1}{2}\times 9.8 \times t^2[/tex]
[tex]t = \sqrt{\frac{30.48}{4.9} }[/tex]
t = 2.5 seconds
Hence, the option (b) is correct.
