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A particle is acted upon by constant forces 4 I+J-3 k and 3 I+J-k which displace it from a point i +2 j +3 k to the point 5 i +4 j + k . The work done in standard units by the forces is given by

Options

  1. A40
  2. B30
  3. C25
  4. D15

Correct answer

A. 40

Step-by-step solution

Work done by the forces F ₁ and F ₂ is ( F ₁+ F ₂ ) d , where d is displacement According to question F ₁+ F ₂=(4 i + j -3 k )+(3 i + j - k )=7 i +2 j -4 k and d =(5 i +4 j + k )-( i +2 j +3 k )=4 i +2 j -2 k . Hence ( F ₁+ F ₂ ) d is 40

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