9231 P21 - Jun 2018 - Q1 - 3 marks
6176
A bullet of mass \(m \mathrm{~kg}\) is fired horizontally into a fixed vertical block of material. It enters the block horizontally with speed \(250 \mathrm{~m} \mathrm{~s}^{-1}\) and emerges horizontally with speed \(70 \mathrm{~m} \mathrm{~s}^{-1}\) after 0.04 s . The block offers a constant horizontal resisting force of magnitude 450 N . Find the value of \(m\).
