Question

A jet accelerates at a=3.92 m/s^2 from rest until it reaches its takeoff velocity of 360 km/hr. It has to travel for 5 seconds at its takeoff velocity before taking off. What's the minimum distance that the jet will travel on the runway?

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4. A 3 kg weight is dropped from 3 meters up. What is the impulse the weight exerts on the ground as it lands and comes to rest?
5. A multi-stage model rocket uses up its fuel, flying up to a height of 250 m. The rocket then explodes, sending its top half upward, while its bottom half loses all of its speed after the explosion and freely falls to the ground. Just after the explosion, the top half is moving at a speed of 200 m/s. How fast was the whole rocket moving just before it exploded?

Answer 1

Accleration of jet is a = 3.92m/s^2

It starts from rest. u = 0 m/s

It reaches final velocity of 360km/hr or 100 m/s

it travels with that speed for 5 sec .

The distance travelled by the jet while accletating is

where s is the distance

The distance travelled by the jet while moving at 100 m/s for 5 secs is

Total distance travelled is 1275.51 + 500 = 1775.51m or 1.77 Km

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