An object is dropped from the top of a tower. If it takes 4s for it to reach the ground, calculate the height of the tower.(g = 10 ms-2, ignore air resistance)
-
A.
20m -
B.
40m -
C.
80m -
D.
160m
Correct Answer: Option C
Explanation
H = (frac{1}{2} gt^2)
(frac{1}{2} times 10 times 4^2 = 80)