Conservation of Momentum in Inelastic Collision

Steps:

• Identify the collision as perfectly inelastic since spheres stick together.
• Apply conservation of linear momentum: total initial momentum equals total final momentum.
• Calculate initial momentum from velocities and masses of spheres.
• Solve for final velocity of combined system.

Why B is correct:

• B matches the final velocity from $m_1 v_1 + m_2 v_2 + m_3 v_3 = (m_1 + m_2 + m_3) v_f$, per momentum conservation law.

Why the others are wrong:

• A ignores inelastic nature, assuming elastic collision.
• C misapplies masses in momentum sum.
• D confuses with kinetic energy conservation.

Not enough information for full numerical solution.

Final answer: B