Given that (q = 9i + 6j) and (r = 4i – 6j), which of the following statements is true?
-
A.
r and q are collinear -
B.
r and q are perpendicular -
C.
The magnitude of r is 52 units -
D.
The projection of r on q is (sqrt{117}) units.
Correct Answer: Option B
Explanation
The dot product of two perpendicular forces = 0
((9i + 6j).(4i – 6j) = 36 – 36 = 0)
Hence, r and q are perpendicular.