00:01
So we're considering a train.
00:04
If we were to draw the picture of it, we've got the three engines, which have a mass of 3m, and they are essentially pulling the rest of the cars, of which there are 22, by applying a force that causes the entire thing to accelerate in the picture i've drawn to the right.
00:33
We're told that each of the masses is 6 -6 -4 -1 -3 -8 kilograms, and that the total force of friction on the entire train is 6 -9 -8 -28 -2 -3.
01:01
But it says this is evenly distributed among all of the cars and engines, so that means that the friction for each car is going to be, well, between the cars and engines, there are 25 total.
01:16
So it'll be that number divided by 25, which is 27952 .92.
01:31
And we want to figure out if the acceleration, of the train is 0 .039 meters per second squared.
01:45
What is the magnitude of the force coupling the engines to the first rail car? so if we draw free body diagram for the rail cars as a whole, then we know that there must be a force that is coupling.
02:13
The rail cars to the engine...