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The resultant of two forces P~N and 3 ~N is a force of 7 ~N . If the direction of 3 ~N force were reversed, the resultant would be 19 ~N . The value of P is

Options

  1. A5 ~N
  2. B6 ~N
  3. C3 ~N
  4. D4 ~N

Correct answer

A. 5 ~N

Step-by-step solution

aligned & 7^2=P^2+3^2+2 3 P (1) & ( 19 )^2=P^2+(-3)^2+2 (-3) P (2) aligned adding we get 68=2 P^2+18 P=5 .

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