An object is placed in a medium of refractive index 3 . An electromagnetic wave of intensity $6 \times 10^8 \mathrm{~W}$ / $\mathrm{m}^2$ falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space $=3 \times 10^8 \mathrm{~m} / \mathrm{s}$ ):