Answer:
The time for the rock to reach the bottom is 4.02 seconds.
Explanation:
Given;
mass of the rock, m = 5 kg
height of the rock fall, h = 79 meters
The time to drop to the given height is given by;
[tex]t = \sqrt{\frac{2h}{g} }[/tex]
where;
t is the time to fall to the bottom
g is acceleration due to gravity = 9.8 m/s²
[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2*79}{9.8} }\\\\t = 4.02 \ s[/tex]
Therefore, the time for the rock to reach the bottom is 4.02 seconds.