Think you just answered your own question there....
Most of the plans to raise the Titanic were impracticable due to the great depth of the ocean.
it is impracticable because the time period of sampled impulse is 0 i.e t=0 and in real life it is impossible to produce a signal of 0sec.
the second expedient is as impracticable as the first would be unwise.
i do not know how to use embalming in a sentence. (there is the sentence)
So- you are asking when to use 'when' in a sentence. When you are asking how to use when in a question, you are already using when in a sentence, because a question actually is a sentence. I like to use when in a sentence whenever I like.
How do you use sedition in a sentence
use contingency in a sentence?
use adainty as sentence
Can you use abstemious in a sentence?
use inmates in sentence
use figureatively in a sentence
Use it in a big sentence.