Linear Momentum and Second Law of Motion: Practice Problem & Solution

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Linear Momentum and Second Law of Motion. Understanding the underlying formula is key to arriving at the correct answer below:

Masses \( m_1 = 0.2 \text{ kg}, m_2 = 0.2 \text{ kg}, m_3 = 0.6 \text{ kg} \). Momentum of first two parts: \( P_1 = 0.2 \times 30 = 6 \text{ Ns} \), \( P_2 = 0.2 \times 30 = 6 \text{ Ns} \). Since they are perpendicular, their resultant momentum \( P_{12} = \sqrt{6^2 + 6^2} = 6\sqrt{2} \text{ Ns} \). By conservation of momentum, \( P_3 = P_{12} = 6\sqrt{2} \text{ Ns} \). Velocity of bigger part \( v_3 = P_3 / m_3 = (6\sqrt{2}) / 0.6 = 10\sqrt{2} \text{ m/s} \).