Answer:
Option A. about 1 seconds
Explanation:
Let the initial speed u and the final speed v
Time t , distance s and acceleration of gravity g
The equation of motion are:
v = u + gt ⇒(1)
s = ut + 0.5 gt² ⇒(2)
v² = u² + 2gs ⇒(3)
Marques drops a plate from a height of 5 feet.
So, u = 0 , s = 5 ft , g = 9.8 m/sec²
Substitute at (2)
s = ut + 0.5 gt²
5 = 0 * t + 0.5 * 10 * t²
∴ t² = 5/(0.5*9.8) = 1.02
∴ t = √1.02 = 1.01 seconds ≈ 1 seconds (to the nearest integer)
The answer is option A. about 1 seconds