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A particle of mass 5kg is at rest under the action of three forces, F; -8i - 2j, F; -ai + bj, and F; -a1 - a. Find the values of the constants a and b. The direction of the force F; is reversed. Find the acceleration of the particle. Give your answer in vector form. A. a = -8i + 2j B. a = 8i - 2j C. b = 2 D. a = -8i + 2j, b = -1

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Final answer:

The values of constants a and b can be found by setting the sum of the given forces equal to zero (since the particle is at rest), and solving for a and b. The acceleration of the particle when the force F3 is reversed is given by -F3/m.

Step-by-step explanation:

To solve this problem, we must first apply Newton's second law of motion that states the vector sum of the forces acting on a body is equal to the mass of the body times its acceleration vector (i.e. Fnet = ma). As the particle is at rest, the net force (and hence, the acceleration) is zero. Considering the given forces:

  • F1 = -8i - 2j
  • F2 = -ai + bj
  • F3 = -a1 - a

The sum of these forces must be equal to zero, hence:

-8i - 2j - ai + bj - a1 - a = 0

This equation can be separately solved for i and j coordinates to find the values of constants a and b. After finding a and b, we know that the force F3 is reversed, therefore the resultant acceleration will be -F3/m. This can be written in vector form as a = -(-a1 - a)/m = a1/m + a/m.

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