Question

How far will a brick starting from rest fall freely in 3 seconds

Answer 1

When object falls freely we can say

its initial speed will be ZERO

and its acceleration due to gravity must be

$a = g = 9.8 m/s^2$

Now we need to find the distance of free fall in 3 s of time

So here we will use kinematics

$y = v* t + \frac{1}{2} at^2$

now we will plug in all values in it

$y = 0 + \frac{1}{2}* 9.8 * 3^2$

$y = 44.1 m$

So it will fall by total distance of 44.1 m