Question

A helicopter is flying (moving) from 180 m from land ,at constant velocity of 45 ms-1 . If an object falls down from that helicopter, how much time it will take to reach the land? ( please provide accurate answer with steps, equations)​

Answer 1

It will take 3.0 s

Step by step explanation:-

We want to find the time it will take the object to reach the land.

To do this, we apply one of Newtons equations of motion:

$s = ut + \frac{1}{2}gt^{2}$

where s= distance/height

u = initial velocity

g = acceleration due to gravity

t = time

From the given question, we have :

$s = 180m \\ u = 45m/s \\ g = 9.8m/{s}^{2}$

Now substitute the given values into the equation and solve for t :

$180 = 45t + ( \frac{1}{2} \times 9.8 \times {t}^{2})$

$= > 180 = 45t + 4.9 {t}^{2}$

$= > 4.9 {t}^{2} + 45t - 180 = 0$

Solving the above quadratic equation, using quadratic formula :

$= > t≈3.0s;t = - 12.2s$

Since time cannot be negative,

$t = 3.0s$

So, it will take 3.0 s to reach the land.