• question_answer Particle A moves along X-axis with a uniform velocity of magnitude 10 m/s. Particle B moves with uniform velocity 20 m/s along a direction making an angle of ${{60}^{o}}$ with the positive direction of X-axis as shown in the figure. The relative velocity of B with respect to that of A is A)  10 m/s along X-axis B)  $10\sqrt{3}\,m/s$along Y-axis (perpendicular to X-axis) C)  $10\sqrt{5}\,m/s$along the bisection of the velocities of A and B D)  30 m/s along negative X-axis

The component of velocity of B along x-direction ${{v}_{Bx}}=20\cos {{60}^{o}}=20\times \frac{1}{2}=10\,m/s$ ${{v}_{A}}=10\,\hat{i}\Rightarrow {{v}_{B}}=10\hat{i}+10\sqrt{3}j$ ${{v}_{BA}}={{v}_{B}}-{{v}_{A}}=10\hat{i}+10\sqrt{3}\hat{j}-10\hat{i}=10\sqrt{3}\hat{j}$