NEET 2016 Physics and Chemistry Paper 2

A bullet of mass 10 g moving horizontally with a velocity of 400ms–1 strikes of wooden block of mass 2 kg which is suspended by a light inextensible string of length 5 m. As a result the centre of gravity of the block is found to rise a vertical distance of 10 cm. The speed of the bullet after it emerges out horizontally from the block will be