Question

In a nuclear magnetic resonance (NMR) lab, the liquid nitrogen cooling system for a 20 kg superconducting magnet fails, causing the magnet to rapidly "quench", overheat, and explode into three fragments. A 5 kg fragment flies directly west at 18 m/s. A 4 kg fragment flies directly south at 21 m/s a) What direction does the third fragment go? Enter your answer as an angle in degrees, northwards from east (counterclockwise as seen from above) degrees north of east b) How fast is it moving? m/s

Answer 1

From conservation of momentum m_1 v_1^bar + m_2 v_2^bar + m_3 v_3^bar = 0 - 5 times 18 i^- 4 times 21 j^= 11 v_3rightarrow = 0 v + 3^rightarrow = 5 times 18/11 i^+ 4 times 21/11 j^direction theta = tan^- 1[4 times 21/11/5 times 18/11] theta = 43 degrees north of east speed v_3 = squareroot (5 times 18/11)^2 + (4 times 21/11)^2 v_3 = 11.2 m/s