A Boeing 777 jet engine, the world's largest, has a power output of 82 MW. It burns jet fuel with an energy density of 43 MJ /kg. What is the engine's fuel consumption rate, in kg/s, if its efficiency is 30%?

Video transcript

Hey, everyone. So this problem is dealing with heat engines. Let's see what it's asking us in an underwater research facility. Scientists built a power generator to provide sustainable energy for their deep sea operations. This novel generator uses a specific fuel with an energy density of 40 mega joules per kilogram to produce megawatts of power with an efficiency of 35%. What is this fuel consumption rate of this underwater power generator? And that's going to be in units of kilograms per second. Our multiple choice answers in units of kilograms per second are a 6.79 V 2. C 7.78 and D 9.14. Ok. So this problem is straightforward. As long as we can recall, the fuel consumption rate equation which is C our fuel consumption rate is equal to p our power divided by a or sorry epsilon. Our energy density multiplied by a hour efficiency. And so we were given all of these values in the problem. So it's a plug and chug from there. We just need to keep an eye on our units. So our power is megawatts. So that's 95 times 10 to the six watts, keeping everything in standard units multiplied by our energy density 40 mega joules. So that's 40 times 10 to the six joules per kilogram multiplied by our E efficiency, which is simply 0.35 we plug that into our calculator and we get 6. kg per second and that aligns with answer choice. A so a is the correct answer for this problem. That's all we have for this one. We'll see you in the next video. Mhm.