Two balls of masses m and 2m are dropped from a height h. Neglecting air resistance, which hits the ground with greater momentum? MCQ with Answer and Explanation

Explanation:
Rayleigh scattering by air molecules, shorter wavelengths (blue) scattered more.

Explanation:
Internal forces cancel in pairs (third law), so net external force = 0 ⇒ dp/dt = 0 (second law) ⇒ momentum constant. Memory aid: 'Momentum conservation ⇔ no external force ⇔ action-reaction pairs'. Mechanics foundation frequently tested in competitive exams.

Explanation:
During phase change (melting), heat energy (latent heat) is used to overcome intermolecular forces, increasing potential energy while kinetic energy (hence temperature) remains constant. Temperature reflects average kinetic energy; since it doesn't change, kinetic energy is unchanged. The energy breaks hydrogen bonds in ice, allowing molecules to move freely in liquid. Memory tip: 'Latent heat changes state, not temperature'. This conceptual question tests understanding of microscopic interpretation of phase changes, frequently examined in competitive tests to assess depth beyond formula recall.