question_answer

A particle is moving eastwards with a velocity of\[5m{{s}^{-1}}\]. In 10 s, the velocity changes to\[5\text{ }m{{s}^{-1}}\]northwards.  The average acceleration in this time is     AIEEE  Solved  Paper-2005

A) \[\frac{1}{\sqrt{2}}m{{s}^{-2}}\]towards north-east

B) \[\frac{1}{2}m{{s}^{-2}}\]towards north

C) zero

D) \[\frac{1}{\sqrt{2}}m{{s}^{-2}}\]towards north-west

Correct Answer: D

Solution :

Given, (unit vectors are assigned in accordance to directory given below) Change in velocity, Now, the average acceleration (in magnitude) For direction, Average acceleration is towards north-west.