repeating an effect for all files in a project

Hi, I want to add two effects to hundreds of files within a project, but there’s an issue. For example, if I add 0.1 seconds of silence to the end of each file, it will take the longest file, then add 0.1 seconds to that, so the smaller files would have over 1 second of silence.

So how do I add an effect to all files in a project without the other files effecting each other?

Audacity 2.2.1

I don’t understand what you mean by “files within a project”. Do you mean tracks? Do you mean WAV or AIF files?
I also don’t understand what you mean by “without the other files effecting each other”.
– Bill

Yes, I mean tracks. What I mean about affecting each other is that if I add 1 second of silence to one track, then it will actually add 1 second to the longest track, then every other track will add 1 second plus the difference between the longest track the current track.

Example:
1.5 second track + 1 second silence = 2.5 seconds
1 second track + 1 second silence = 2.5 seconds (should be 2 seconds)