An aircraft travelling at 600 km/hr accelerates steadily at 10 km/hr per second. Taking the speed of sound as 1100 km/hr at the aircraft’s altitude, how long will it take to reach the ‘sound barrier’?

Kashyap abhishekCompetent

# An aircraft travelling at 600 km/hr accelerates steadily at 10 km/hr per second. Taking the speed of sound as 1100 km/hr at the aircraft’s altitude, how long will it take to reach the ‘sound barrier’?

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## Arjun

Given,

u = 600 km/h = 600 ×

^{5}/_{18}m/s =^{1500}/_{9}m/sa = 10 km/h per sec = 10 ×

^{5}/_{18}m/s per sec =^{25}/_{9}m/s²The aircraft has to cross sound barrier.

So, v = 1100 km/h = 1100 ×

^{5}/_{18}m/s =^{2750}/_{9}m/sUsing, v = u + at

⇒

^{2750}/_{9}=^{1500}/_{9}+^{25t}/_{9}⇒2750 = 1500 + 25t

⇒2750 – 1500 = 25t

⇒1250 = 25t

⇒t = 50 sec

Hence, the aircraft will reach the sound barrier in 50 sec.

## Shivansh Preet

Given,u = 600 km/h = 600 × 5/18 m/s = 1500/9 m/sa = 10 km/h per sec = 10 × 5/18 m/s per sec = 25/9 m/s²The aircraft has to cross sound barrier.So, v = 1100 km/h = 1100 × 5/18 m/s = 2750/9 m/sUsing, v = u + at⇒ 2750/9 = 1500/9 + 25t/9⇒2750 = 1500 + 25t⇒2750 – 1500 = 25t⇒1250 = 25t⇒t = 50 secHence, the aircraft will reach the sound barrier in 50 sec.