The work done by a conservative force in moving a particle along a closed path is:
A. Positive
B. Zero
C. Depends on path
D. Negative
Answer: Option B
Solution (By JKExamLibrary)
Conservative forces (gravity, spring, electrostatic) have path-independent work; work done over any closed loop is zero. This defines conservative forces and enables potential energy definition. Non-conservative forces (friction) have non-zero closed-path work. Memory aid: 'Conservative force: ∮F·dr = 0; enables energy conservation'. This mechanics concept is frequently tested in competitive exams. Always link conservative forces to potential energy and mechanical energy conservation; this is foundational for advanced physics problem-solving.
Explanation:
Let distance d, usual time t hours. d/5 = t + 10/60, d/6 = t - 5/60. Subtract: d/5 - d/6 = (15/60) => d/30 = 0.25 => d = 7.5 km. Commonly asked.
Explanation:
Higher pressure raises boiling point, so water can reach temperatures above 100°C, cooking food faster. At high altitudes, pressure cooker compensates for lower atmospheric pressure.
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