Physics · PYQ NEET UG 2022
हिन्दीA shell of mass \( m \) is at rest initially. It explodes into three fragments having mass in the ratio \( 2 : 2 : 1 \). If the fragments having equal mass fly off along mutually perpendicular directions with speed \( \upsilon \), the speed of the third (lighter) fragment is:
Correct answer · Option 1
\( 2\sqrt{2}\upsilon \)
Explanation
By conservation of momentum, \( \vec{p}_3 = -(\vec{p}_1 + \vec{p}_2) \). Magnitude \( m_3 v_3 = \sqrt{(m_1 v)^2 + (m_2 v)^2} \Rightarrow 1 \cdot v_3 = \sqrt{(2v)^2 + (2v)^2} = 2\sqrt{2}\upsilon \).