question_answer

A particle changes its velocity from \[6\,m{{s}^{-1}}\] towards east to \[6\,m{{s}^{-1}}\] towards north in 3 second. Then magnitude of its acceleration will be:

A) 0                             

B) \[2\,m{{s}^{-1}}\]

C) \[2\sqrt{2}m{{s}^{-2}}\]   

D) \[6\sqrt{2}\,m{{s}^{-2}}\]

Correct Answer: C

Solution :

Average ace. \[2(1+k)\,-(k+2)\,(1-k)=0\] \[{{k}^{2}}+3k=0\] \[k=0\]