Is the word "strew" related to "straw?" [closed]

It seems to me that straw is in fact strewn. The ancient meaning of "strew" is "to lay flat." Anyway, they sound like related words.

I have noticed also that words in English which start with "str" tend to be words that relate to a protracted rather than an abrupt action.

Yes, there is a relation, as Etymonline shows:

apparently literally "that which is scattered or strewn," related to streowian (see strew)

About an ancient meaning of lay flat I'm not so sure, as the same source states:

from PIE root *stere- "to spread."

Which would not be similar but not the same (I can lay flat a tree, but spreading it would be rather difficult)

About abrupt actions: how about strike? I'm not sure you're on to anything there.

Straw and strew share the same phonaestheme str-.
Phonaesthetics is the association of certain sounds with certain meanings.

The phonaestheme str- often conveys narrowness or dispersion or spreading out in space.

Examples: Straddle, strain, straw, strew, strap etc.

There's a whole slew of examples at DavidAppleYard.

Regarding the interesting and - to my knowledge - novel protracted/abrupt hypothesis I cannot see any evidence that it applies. Here are most of the "str-" verbs, with my own perceived abrupt/protracted classification. The proportions are about equal.

I don't claim this tentative classification to be correct. It is a merely a start and others may reasonably differ.