Answer:
d = 80 m
Explanation:
It is given that,
A rock falls for 4 seconds.
We need to find how far did it fall.
let it cover d distance.
Using equation of motion to find it :
[tex]d=ut+\dfrac{1}{2}at^2[/tex]
Here, u = 0 (at rest initially)
a = g
[tex]d=\dfrac{1}{2}gt^2\\\\d=\dfrac{1}{2}\times 10\times 4^2\\\\d=80\ m[/tex]
It will fall at a distance of 80 m.