Question

A brick is dropped from a height of 80.0 m.
a. How long does it take a brick to reach the ground?

Answer 1

\[\Delta y = v _{i}\Delta t + \frac{ 1 }{ 2 }a \Delta t ^{2}\]

This equation should help (assuming it is dropped from rest). You can solve for time since you have all the other variables.

Answer 2

The above equation is ok

Answer 3

U can try my equation too
h=ut+(1/2)*g*t^2
Given h=80m
u=0
g=9.8m/sec^2
t=?