Practice question

Given: A 2.5 kg ball at 16 m/s collides elastically with a stationary 7.5 kg ball. What is the speed of the 7.5 kg ball after collision? These values define the system as per NCERT data. Formula: For elastic collision: v_{2f = 2 m_1/m_1 + m_2 v_{1i = 2 × 2.5/2.5 + 7.5 × 16 = 5/10 × 16 = 8 m/s .. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Substituting values like 1.2 × 10⁻⁵, 236 J kg⁻¹ K⁻¹, CH₃CH₂NH₂ etc. into the formula and simplifying step by step. Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.