Question

The magnitudes of the three unit vectors (i,ˆ−iˆ and jˆ ) are the same, but their directions are different.
So, the resultant of iˆ and −iˆ is a zero vector. explain the statement

Answer 1

$$\begin{gathered} \mathrm{Magnitude}\mathrm{of}\stackrel{⏜}{\mathrm{i}}=\mathrm{Magnitude}\mathrm{of}\stackrel{⏜}{\mathrm{j}}=\mathrm{Magnitude}\mathrm{of}\stackrel{⏜}{\mathrm{k}}=1 \\ \mathrm{Direction}\mathrm{of}\stackrel{⏜}{\mathrm{i}}=\mathrm{Positive}\mathrm{x}-\mathrm{axis} \\ \mathrm{Direction}\mathrm{of}-\stackrel{⏜}{\mathrm{i}}=\mathrm{Negative}\mathrm{x}-\mathrm{axis} \\ \mathrm{Direction}\mathrm{of}\stackrel{⏜}{\mathrm{j}}=\mathrm{Positive}\mathrm{y}-\mathrm{axis} \\ \mathrm{Direction}\mathrm{of}-\stackrel{⏜}{\mathrm{j}}=\mathrm{Negative}\mathrm{y}-\mathrm{axis} \\ \mathrm{Direction}\mathrm{of}\stackrel{⏜}{\mathrm{k}}=\mathrm{Positive}\mathrm{z}-\mathrm{axis} \\ \mathrm{Direction}\mathrm{of}-\stackrel{⏜}{\mathrm{k}}=\mathrm{Negative}\mathrm{z}-\mathrm{axis} \\ \mathrm{Resultant}\mathrm{of}\hat{\mathrm{i}}\&-\hat{\mathrm{i}}=\hat{\mathrm{i}}-\hat{\mathrm{i}} \\ =\mathrm{Vector}\mathrm{with}\mathrm{zero}\mathrm{magnitude}\mathrm{and}\mathrm{no}\mathrm{definite}\mathrm{direction} \\ =\mathrm{Null}\mathrm{vector} \end{gathered}$$