Answer:
[tex]40\:\mathrm{m}[/tex]
Explanation:
We can use kinematics equation [tex]\Delta y={v_i}^2+\frac{1}{2}at^2[/tex] to solve this problem. Because the metal ball's initial velocity was 0, [tex]{v_i}^2=0[/tex].
Therefore, our equation becomes:
[tex]\Delta y=\frac{1}{2}at^2[/tex] (freefall equation).
[tex]t[/tex] is given as 3 seconds and [tex]a[/tex] is acceleration due to gravity ([tex]9.81\:\mathrm{m/s}[/tex]).
Therefore, our answer is:
[tex]\Delta y = \frac{1}{2}\cdot9.81\cdot3^2=44.145=\fbox{$40\:\mathrm{m}$}[/tex] (one significant figure).
