A body is projected horizontally from a height of 78.4 m with a velocity 10 ms^-1. Its velocity after 3 seconds is : [g = 10 ms^-2] (Take direction of projection on $\overrightarrow{\mathrm{i}}$ and vertically upward direction on $\overrightarrow{\mathrm{j}}$).

• A

  $10\overrightarrow{\mathrm{i}}-30\overrightarrow{\mathrm{j}}$

• B

  $10\overrightarrow{\mathrm{i}}+30\overrightarrow{\mathrm{j}}$

• C

  $20\overrightarrow{\mathrm{i}}-30\overrightarrow{\mathrm{j}}$

• D

  $10\overrightarrow{\mathrm{i}}+10\sqrt{3}\overrightarrow{\mathrm{j}}$