Question

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Practice Problems 2
1. An aeroplane lands on a runway and comes to a stand still in 20 s, when the braking force
acting on its wheels produces a retardation of 5 m/s2. Find the initial velocity of the aeroplane
during touch down in (i) m/s (ii) km/h.
[(i) 100 m/s (ii) 360 km/h)
​

Answer 1

Answer:

ans is 1. 100m/s 2. 360km/h

Explanation:

Hope it helps !

Answer 2

Hello there !

Given :-

• Final velocity, v = 0 m/sec.
• time = 20sec.
• retardation = -5m/sec.²

solution:-

let's find the value of initial velocity (u) in m/sec.

by using the formula :-

$\huge \fbox \blue{v=u+at}$

0 = u + -5(20)

0 = u + (-100)

0 = u - 100

u = 100 m/sec.

to find the value in km/ hr. multiply the answer with 18/5

$\frac{18}{5} \times 100 \\ ⇒ 20 \times 18 \\⇒ 360$

hence, the answer is 360km/hr.

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Hope, it helps ⭐⭐⭐