Our new WitCH, below, comes courtesy of Charlie the Enforcer. Once again, this WitCH is from the 2018 SCSA Mathematical Methods Exam (here and here): it’s the gift that keeps on giving. (And a reminder, WitCH 2 and WitCH 3 still require attention are still unresolved.)

Question 11 and the solution in SCSA’s marking key are below. Happy hunting.

## Update

John has pretty much caught it all. The killer issue is the use of the term “deceleration” in part (c) which, the solution implies, refers to the drone *speeding up* in the southerly direction. This is arguably permissible, since deceleration can be (though is far from universally) defined as a negative acceleration, and since way back in part (a) it was implied that North coincides with the positive *x* direction.

Permissible acts, however, can nonetheless be idiotic: voting Liberal or Republican, for example. And, to use “deceleration” on a high stakes exam to refer implicitly to increasing speed is idiotic. Moreover, to use “deceleration” in this manner *immediately* after explicitly indicating the “due south” direction of motion is truly ruly idiotic. Still not as idiotic as voting Liberal or Republican, but genuinely special-effort idiotic.

That’s enough to condemn the question, even by SCSA standards. But, the question is also awful in many other ways:

- The question is boring and butt ugly.
- No indication is given whether exact or numerical solutions are permitted or required.
- Having a drone an arbitrary 5m up in the sky for a 1D problem is asking for trouble. For example:
- The “displacement” of x(0) = 0 for a drone 5m up is pretty stupid.
- “Where is the drone in relation to the [mysterious] pilot?” Um, kind of uppish?
- “How far has the drone travelled …” is needlessly wordy and ambiguous. If you want a distance, for God’s sake say “distance”.
- Given the position function
*x*(*t*) is at hand, part (c) can easily and naturally be solved by hand. But of course why think about things when you can do mindless calculator crap?