Kinematics Question 5
Question: $ \overrightarrow{A}=2\hat{i}+\hat{j},B=3\hat{j}-\hat{k} $ and $ \overrightarrow{C}=6\hat{i}-2\hat{k} $ . Value of $ \overrightarrow{A}-2\overrightarrow{B}+3\overrightarrow{C} $ would be
Options:
A) $ 20\hat{i}+5\hat{j}+4\hat{k} $
B) $ 20\hat{i}-5\hat{j}-4\hat{k} $
C) $ 4\hat{i}+5\hat{j}+20\hat{k} $
D) $ 5\hat{i}+4\hat{j}+10\hat{k} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ \overrightarrow{A}-2\overrightarrow{B}+3\overrightarrow{C}=(2\hat{i}+\hat{j})-2(3\hat{j}-\hat{k})+3(6\hat{i}-2\hat{k}) $
$ =2\hat{i}+\hat{j}-6\hat{j}+2\hat{k}+18\hat{i}-6\hat{k} $ = $ 20\hat{i}-5\hat{j}-4\hat{k} $
BETA
