A mass of 100g strikes the wall with speed 5m/s at an angle as shown in figure and it rebounds with the same speed. If the contact time is $2\times {10}^{-3}\sec$, what is the force applied on the mass by the wall

Force = Rate of change of momentum 
Initial momentum ${\overrightarrow{\mathrm{P}}}_1=\mathrm{mvsin\theta }\mathrm{\hspace{0.33em}}\widehat{\mathrm{i}}+\mathrm{mvcos\theta }\mathrm{\hspace{0.17em}}\widehat{\mathrm{j}}$
Final momentum ${\overrightarrow{\mathrm{P}}}_2=-\mathrm{mvsin\theta }\mathrm{\hspace{0.33em}}\widehat{\mathrm{i}}+\mathrm{mvcos\theta }\mathrm{\hspace{0.17em}}\widehat{\mathrm{j}}$
$\therefore \overrightarrow{\mathrm{F}}=\frac{\mathrm{\Delta }\overrightarrow{\mathrm{P}}}{\mathrm{\Delta t}}=\frac{-2\mathrm{mvsin\theta }}{2\times {10}^{-3}}$
Substituting m = 0.1 kg, v = 5 m/s, $\mathrm{\theta }$ = 60°
Force on the ball  $\overrightarrow{\mathrm{F}}=-250\sqrt{3}\mathrm{N}$
Negative sign indicates direction of the force