Kinematics Question 583
Question: The vector that must be added to the vector $ \widehat{i}-3\widehat{j}+2\widehat{k} $ and $ 3\widehat{i}-6\widehat{j}+7\widehat{k} $ so that the resultant vector is a unit vector along the y-axis, it’s
Options:
A) $ 4\widehat{i}-2\widehat{j}+5\widehat{k~}~~ $
B)$ -4\widehat{i}-2\widehat{j}+5\widehat{k~}~~ $
C) $ 3\widehat{i}-4\widehat{j}+5\widehat{k~}~~ $
D)Null vector
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Unit vector along y axis =$ \hat{j} $ , so the required vector $ =\hat{j}-[ ( \hat{i}-3\hat{j}+2\hat{k} )+( 3\hat{i}+6\hat{j}-7\hat{k} ) ] $
$ =-4\hat{i}-2\hat{j}+5\hat{k} $
