Correct Answer: Option D

Explanation

u = , H = 20, g = 10

From equation of motion under gravity

H = ut ± \(\frac{1}{2}\)gt², It is falling so g is +ve

H = 0 + \(\frac{1}{2}\)gt²

H = \(\frac{1}{2}\)gt²

2H = gt²

\(\frac{2H}{g}\) = t²

t = \(\frac{\sqrt{2H}}{g}\)

= \(\frac{\sqrt {2 \times 20}}{10}\)

= √4

= 2s

There is an explanation video available below.

• A triangle has sides 8cm and 5 cm and an angle of 90 ° between the . calculate the smallest... Answer this

  1 Answers   ·   Mathematics   ·   1 hour ago
• What course can I study with this results 👇 Mathematics B3 Economics A1 Civic Education B2 English C5 Marketing B3... Answer this

  0 Answers   ·   Economics   ·   4 hours ago
• Please I lost the simcard I used to register my jamb how can I get to see my result please? Answer this

  2 Answers   ·   20 hours ago