It was already determined that the jet velocity of this engine is 376 metres per second. Suppose that this Boeing 777 flies at 11 kilometres at M=0.82, what is then the jet efficiency of this engine (in percent)?

Answer 1

To find the jet efficiency of the engine, we need to calculate the ratio of the actual velocity of the jet to the ideal velocity of the jet.

First, let's convert the speed of the Boeing 777 from kilometers per hour to meters per second.

11 kilometers is equal to 11,000 meters.
So, the speed of the Boeing 777 is 11,000 meters divided by 1 hour, which is 11,000 meters/3,600 seconds, which is approximately 3.06 meters per second.

Next, we need to calculate the ideal velocity of the jet.
The ideal velocity of the jet is the speed of sound, which is approximately 343 meters per second.

So, the ratio of the actual velocity to the ideal velocity is:
3.06 meters per second / 343 meters per second = 0.00893

Finally, we multiply this ratio by 100 to find the jet efficiency as a percentage:
0.00893 * 100 = 0.893%

Therefore, the jet efficiency of this engine is approximately is 0.893%.