the car problem in my text uses the unit vector, and the second one doesn't...
The second problem is more complex and requires vectors to take care of the 3 directions involved. The first (car) problem has only one direction so no need for vectors.
but it did the opposite of just that.
the car used 'unit' vector....
while the second does not use the 'unit' vector
The first problem is asking for a moment about an axis. I'm pretty sure this is why you have to employ the unit vector in your calculations. If i recall correctly (been awhile since I was in statics) the unit vector here will be j or [0i 1j 0k]. Is that familiar?
The second problem is asking for a moment about a point.
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