Question

A body falls from a height 100 meters.After 2 sec if gravity disappears,find the total time it would take to reach the ground (g=10m/s)

Answer 1

Hey buddy !!!

Here's the answer you are looking for

The force that was pulling it towards the ground has disappeared. Since the external unbalanced force disappears, the acceleration becomes 0. So now it will travel with the velocity that it has gained during its 2sec journey.

In the 2 sec,
initial velocity (u) = 0
acceleration (a) = g = 10m/s²

So final velocity(v)
= u + at
= 0 + 10(2)
=20m/s

In the 2sec distance travelled (s)
= ut + 1/2at²
=0(2) + 1/2 (10)(2²)
= 0 + 5(4)
=20m

Now, the body has to cover 80m.And it's velocity is 20m/s and acceleration is 0.

So time taken to reach the ground
= 80 / 20 sec
=4sec.

It would take an extra 4sec to reach the ground.

Therefore, the total time it will take to reach the ground is (4 + 2) sec = 6 sec

★★ HOPE THAT HELPS ☺️ ★★