00:02
A airplane has a mass of 68 ,000 kilograms and ignoring the drag, we need to know how much work these engines are going to have to do to get this thing off the ground when its takeoff speed is 250 kilometers per hour.
00:20
So, work and energy is the focus here, and the work at this moment is going into generating kinetic energy.
00:32
So the thought we need to keep in mind is there's a couple definitions or formulas for the work.
00:37
Work can be considered as the change in kinetic energy, and work can also be considered as force times displacement.
00:47
Now, since we're starting from rest and speeding up, we're talking about changing the kinetic energy.
00:52
We're adding energy to this airplane, and the engines are going to do that.
00:56
So we have to consider it from this point of view.
01:00
So how much kinetic energy is there? well, it's going to have a takeoff velocity of 250 kilometers per hour, which is inconvenient because that's not the units we want to use...