Waves Superposition (Drawing) Question

[man0005]

Hey guys,

Just wondering if someone could check if I have done these pulse drawings correctly, particularly the composite waveforms as they pass through.
Would greatly appreciate if someone could tell me what the dotted lines in the example (bolded ones on the right) are for and whether I need them in my drawings.

[pi]

I think what you have done is wrong...

What you are supposed to do (I think) is a methods similar to addition of ordinates. Notice how on the examples, there is a dotted line. This dotted line shows the two peaks if there was none of this 'addition' or composition. Now, notice how the black lines do not go over the dotted ones? That is because they are being added together in parts of intersection.

For example, at t=45, notice how the peak of the peak (bad wording) is double the height of the normal one, this is because they are being added together (use the background dotes to help you do that): normal peak + normal peak = 2 dots up + 2 dots up = 4dots (for t=45 peak).

[man0005]

ohh okay, i think i get it now.
would it be right now?

[pi]

Looks alright to me now

[man0005]

sweet, just have one more for you to check

[pi]

Yep, you've got the idea now, its much easier once you get the dotted lines stuff