Function Notation to Express a Question

[Nero]

Part B of the following problem seems to be fairly straightforward, but I can't seem to complete it properly. I might be overthinking the problem entirely.

Would anyone be willing to help?

 

[Dr.Peterson]

What answer did you enter that was rejected?

It is indeed a straightforward question. It would have been nice if they had explicitly stated that v(t) is the velocity in miles per hour, but that's pretty obvious.