question_answer

A truck travelling due north at 20 ms-1 turns west and travels with same speed. What is the change in velocity?

A) \[20\sqrt{2}m{{s}^{-1}}\]south-west

B)  \[40m{{s}^{-1}}\]south-west

C) \[20\sqrt{2}m{{s}^{-1}}\]north-west

D) \[40m{{s}^{-1}}\]north-west

Correct Answer: A

Solution :

                Change in velocity \[=\sqrt{{{(20)}^{2}}+{{(20)}^{2}}}=20\sqrt{2}\] along north-east or south-west