A bullet of mass `10g` moving horizontally with a velocity of `400 ms^(-1)` strickes a wooden block of mass `2 kg` which is suspended by a light inextensible string of length `5m`. As a result, the center ofgravity of the block is found to rise a vertical distance of `10cm` . The speed of the bullet after it emerges out hirizontally from the block will be