Question

Marques drops a plate from a height of 5 feet. When will the plate hit the ground?

Answer 1

Answer:

Option A. about 1 seconds

Step-by-step 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