Explanation:
v_e = √(2GM/R): depends on planet's M and R, independent of projectile mass or launch direction. Memory tip: 'v_e ∝ √(M/R); property of planet, not projectile'. Gravitation concept frequently tested in competitive exams.
Explanation:
Law of conservation of energy states total energy (all forms) is conserved in isolated systems. For mechanical energy (KE + PE) to be conserved, only conservative forces (like gravity, spring) must act; non-conservative forces (friction) convert mechanical energy to heat. Option C precisely states this condition. Options A and B are incorrect as KE and PE individually vary. Option D is false as thermal energy can exist. Memory tip: 'Mechanical energy conserved ⇔ no non-conservative work'. This nuanced understanding is critical for energy problems in competitive exams, where distractors often omit the conservative force condition.
Explanation:
Copper has free electrons, very low resistivity, excellent conductor. Glass, rubber, wood are insulators. Silver best conductor, but copper widely used. Graphite conducts but non-metal.
No comments yet. Be the first to start the discussion!