A body of mass 5kg at rest is acted upon by two mutually perpendicular forces 6N and 8N simultaneously. Its kinetic energy after 10s is ___ in (J)

The body will have accelerations of $\frac{6}{5}{\mathrm{ms}}^{-2}$ and $\frac{8}{5}{\mathrm{ms}}^{-2}$ in perpendicular directions.

After 10sec the speed in each direction will be $12{\mathrm{ms}}^{-1}$ and $16{\mathrm{ms}}^{-1}$ in respective directions.

The total gain in kinetic energy will be $\mathrm{K}=\frac{1}{2}.5.{\left(12\right)}^2+\frac{1}{2}.5.{\left(16\right)}^2=1000\mathrm{J}$