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99 Percentile Qs Bank for JEE MainPhysicsGravitation

A straight rod of length L extends from x = a to x = L + a . Find the gravitational force it, exerts on a point mass m at x = 0 if the linear density of rod μ = A + B x 2

Options

  1. AG m A a + B L
  2. BG m A 1 a - 1 a + L + B L
  3. CG m B L + A a + L
  4. DG m B L - A a

Correct answer

B. G m A 1 a - 1 a + L + B L

Step-by-step solution

∴ d F = G m ( μ d x ) x 2 F = G m   ∫ a a + L A + B x d x x 2 F = G m A 1 a - 1 a + L + B L

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