A body of mass 2 kg is raised to height 10 m and dropped. Potential energy just before dropping is (g=10) MCQ with Answer and Explanation

Explanation:
v_esc ∝ √(M/R). New ∝ √(4M/2R) = √(2M/R) = √2 √(M/R) = √2 v.

Explanation:
Q = mL = 3×336 = 1008 kJ. Direct latent heat formula application. Memory tip: 'Phase change: Q = mL; no temperature change'. Calorimetry calculation frequently tested in competitive exams.

Explanation:
When a wave (like light or sound) changes mediums, its velocity changes due to the new medium's optical or mechanical density. Wavelength changes proportionally with velocity (v = fλ). However, frequency is determined solely by the source generating the wave and the energy of the photons/particles, and it remains absolutely constant.