Vectors Question 153

Question: A vector $ \overrightarrow{A} $ points vertically upward and $ \overrightarrow{B} $ points towards north. The vector product $ \overrightarrow{A}\times \overrightarrow{B} $ is

[UPSEAT 2000]

Options:

A) Zero

B) Along west

C) Along east

D) Vertically downward

Show Answer

Answer:

Correct Answer: B

Solution:

Direction of vector A is along z-axis \ $ \vec{A}=a\hat{k} $ Direction of vector B is towards north \ $ \vec{B}=b\hat{j} $ Now $ \vec{A}\times \vec{B}=a\hat{k}\times b\hat{j}=ab(-\hat{j}) $ \ The direction is $ \vec{A}\times \vec{B} $ is along west.