Kinematics Question 294

Question: Two vector A and B have equal magnitudes. Then the vector A + b is perpendicular to

Options:

A) x-axis

B) y-axis

C) z-axis

D) Line at equal angles to all the three axes

Show Answer

Answer:

Correct Answer: A

Solution:

$ \vec{L}=\vec{r}\times \vec{p}= \begin{vmatrix} {\hat{i}} & {\hat{j}} & {\hat{k}} \\ 1 & 2 & -1 \\ 3 & 4 & -2 \\ \end{vmatrix} $

$ =-\hat{j}-2\hat{k} $

i.e. the angular momentum is perpendicular to x-axis.



NCERT Chapter Video Solution

Dual Pane