Question

An aeroplane has a run of 500 m to take off from the runway. It starts from rest and moves with constant acceleration to cover the runway in 30 sec. what is the velocity of the aeroplane at the take off? Ans: 120 km/hr.​

Answer 1

Solution:

Given:

An aeroplane has a run of 500 m to take off from the runway. It starts from rest and moves with constant acceleration to cover the runway in 30 sec.

We know that:

$\bullet$ $\boxed{\sf{s = ut + \frac{1}{2} + at^{2}}}$

By substituting the values, we get:

$\implies$ s = ut + 1/2 + at^2

$\implies$ s = 1/2 + at^2 ( u = 0 )

Now:

$\implies$ a = 2s/t

$\implies$ a = 2 × 500 / (30)^2

$\implies$ a = 1000/900

$\implies$ a = 10/9 m/s^2

We know that:

$\bullet$ $\boxed{\sf{v = u + at}}$

By substituting the values, we get:

$\implies$ 300/9 × 3600/1000 km/hr

$\implies$ 300/9 × 36/10

$\implies$ 120 km/hr

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Answered by: Niki Swar, Goa❤️