Is it a phrase or clause more than fifty miles per hour.

phrase

Explanation:

In everyday speech, a phrase is any group of words, often carrying a special idiomatic meaning; in this sense it is synonymous with expression. In linguistic analysis, a phrase is a group of words that functions as a constituent in the syntax of a sentence, a single unit within a grammatical hierarchy. a small group of words standing together as a conceptual unit, typically forming a component of a clause.

to show how the cables work.