Kinematics Question 58
Question: Assertion : Vector addition is commutative. Reason : $ (\vec{A}+\vec{B})\ne (\vec{B}+\vec{A}). $
Options:
A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
B) If both assertion and reason are true but reason is not the correct explanation of the assertion.
C) If assertion is true but reason is false.
D) If the assertion and reason both are false.
Show Answer
Answer:
Correct Answer: A , C
Solution:
$ \vec{A}.\vec{B}=\vec{B}.\vec{C} $
therefore $ AB\cos {\theta_1}=BC\cos {\theta_2} $ A = C, only when $ {\theta_1}={\theta_2} $
So when angle between $ \vec{A} $ and $ \vec{B} $ is equal to angle between $ \vec{B} $
and $ \vec{C} $ only then $ \vec{A} $ equal to $ \vec{C} $
Since vector addition is commutative, therefore $ \vec{A}+\vec{B}=\vec{B}+\vec{A}. $
