00:01
What is their separation would both trains have stopped? so i don't have the figure, but i'm going to supply some values so that you can do this problem.
00:09
So we want to first find the velocity or the slope of the solid line.
00:15
So let's say our slope of our solid line is equal to negative 42 over 5 meters per second squared.
00:31
Now for the first train, we can write our equation of motion.
00:34
I can write x1 of t is equal to 0 plus vs times t plus acceleration 1 t squared over 2.
00:43
Now for our second line, our dash line, we are also going to need the slope of our dash line.
00:49
Let's say it's equal to 31 .5 over 4, which is just our acceleration 2.
00:56
Now our equation of motion is going to be our distance apart 200 minus 31 .5 .5.
01:07
5 t plus a 2 t squared over 2 now when both trains have stopped the velocities are equal to 0 so let's say the first train stops after 5 seconds so let's say x1 of 5 is equal to are 42 times 5 minus 42 over 5 times 5 or times 5 squared over 2 so let's plug this into a calculator and so we get 105 meters...