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)
20m
40m
80m
160m
Correct answer is C
H = \(\frac{1}{2} gt^2\)
\(\frac{1}{2} \times 10 \times 4^2 = 80\)