Question

31. The vector i represents 1 mile per hour east, and the
i
vector j represents 1 mile per hour north. Maria is
jogging south at 12 miles per hour. One of the
following vectors represents Maria's velocity, in miles
per hour. Which one?
A. -12i
B. -12j
C. 12i
D. 12j
E. 12i + 12j

Answer 1

Answer:

B

Explanation:

The north is opposite to the south

So the vector $j$ represents 1 mile per hour south.

Maria is jogging south at 12 miles per hour.

Therefore, the vectors $12j$ represents Maria's velocity. The correct answer is B.