Question:medium

A particle moves along the x-axis under a force $ F(x) = 6x^2 $ N. The work done by this force in moving the particle from $ x = 1 \, \text{m} $ to $ x = 2 \, \text{m} $ is:

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When force is a function of position, use definite integration: \[ W = \int_{x_1}^{x_2} F(x)\,dx \]
Updated On: Jan 13, 2026
  • 14 J
  • 18 J
  • 24 J
  • 28 J
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The Correct Option is A

Solution and Explanation

The work done by the force $ F(x) = 6x^2 $ from $ x = 1 \, \text{m} $ to $ x = 2 \, \text{m} $ is calculated using the work integral: $ W = \int_{x_1}^{x_2} F(x) \, dx $. Substituting the values: $ W = \int_{1}^{2} 6x^2 \, dx $. Evaluating the integral: $ W = 6 \int_{1}^{2} x^2 \, dx = 6 \left[ \frac{x^3}{3} \right]_{1}^{2} $. This simplifies to: $ W = 6 \left( \frac{2^3}{3} - \frac{1^3}{3} \right) = 6 \left( \frac{8}{3} - \frac{1}{3} \right) = 6 \left( \frac{7}{3} \right) $. The final result is: $ W = 14 \, \text{J} $. Therefore, the work done is 14 J.
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