Kinetic Energy and Momentum: Practice Problem & Solution

Short Solution (Best for NEET):

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

Since kinetic energy \( K \) is the same for both masses, the momentum is proportional to the square root of the mass, \( p = \sqrt{2mK} \). Thus, the ratio of their momenta is \( \frac{p_1}{p_2} = \sqrt{\frac{4m}{9m}} = \frac{2}{3} \).