Abrick is dropped from rest from a height of 4.9 m. how long does it take the brick to reach the ground?

We know the equation of motion , , where s is the displacement, u is the initial velocity, a is the acceleration and t is the time taken.

In this case a brick is dropped from rest from a height of 4.9 m, so displacement, s = 4.9 m

Since the brick is dropped from rest, u = 0 m/s

Acceleration on brick = acceleration due to gravity = 9.81

Substituting

So the brick will reach ground after 1 second.

asthenosphere and convection