Question

A car X is going towards west at a speed of

12 m/sec. Another car Y is going towards north at a speed of 5 m/sec. What is the velocity of car X with respect to the car Y ?

• A. 7 m/sec
• B. 17 m/sec
• C. 13 m/sec
• D. 7/5 m/sec

Answer 1

Answer: (C)

13 m/sec

Answer 2

${\bar{v}}_{x(y)} = {\bar{v}}_{x} - {\bar{v}}_{y}$

$|{\bar{v}}_{x(y)}| = \sqrt{12^{2} + 5^{2}}$ = 13 m/s