if 0<x, y<\(\pi\) and cosx+cosy-cos(x y)=\(\frac{3}{2}\),Then sin x+cos y=?
\(\frac{1}{2}\)
\(\frac{1+\sqrt3}{2}\)
\(\frac{\sqrt3}{2}\)
\(\frac{1-\sqrt3}{2}\)
A body of mass 1000 kg is moving horizontally with a velocity of 6 m/s. If 200 kg extra mass is added, the final velocity (in m/s) is: