The Marksmith AU

The given you read past

A phrase looks like background, so you move on.

Every phrase in the stem is an equation. "At rest" is $v=0$; "terminal velocity" is $\ddot{x}=0$; "remains in contact" is $N \ge 0$; "unit mass" sets $m=1$.

Next time: When stuck, find the given you haven't written down.

Try it: Work one on a block