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You hang a light in front of your house using an
elaborate system to keep the 12-kg object in static
equilibrium (Figure 1). What are the magnitudes of the
forces that the ropes must exert on the knot connecting
the three ropes if 02 = 639 and 03 = 45° ?

Respuesta :

The magnitudes of the forces that the ropes must exert on the knot connecting are :

  • F₁ = 118 N
  • F₂ = 89.21 N
  • F₃ = 57.28 N

Given data :

Mass ( M ) = 12 kg

∅₂ = 63°

∅₃ = 45°

Determine the magnitudes of the forces exerted by the ropes on the connecting knot

a) Force exerted by the first rope = weight of rope

∴  F₁ = mg

     = 12 * 9.81 ≈  118 kg

b) Force exerted by the second rope

applying equilibrium condition of force in the vertical direction

F₂ sin∅₂ + F₃ sin∅₃ - mg = 0  ---- ( 1 )

where: F₃ = ( F₂ cos∅₂ / cos∅₃ ) --- ( 2 )  applying equilibrium condition of force in the horizontal direction

Back to equation ( 1 )

F₂ =  [ ( mg / cos∅₂ ) / tan∅₂ + tan∅₃ ]

   = [ ( 118 / cos 63° ) / ( tan 63° + tan 45° ) ]

   = 89.21 N

C ) Force exerted by the third rope

Applying equation ( 2 )

F₃ = ( F₂ cos∅₂ / cos∅₃ )

    = ( 89.21 * cos 63 / cos 45 )

    = 57.28 N

Hence we can conclude that The magnitudes of the forces that the ropes must exert on the knot connecting are :

F₁ = 118 N, F₂ = 89.21 N, F₃ = 57.28 N

Learn more about  static equilibrium : https://brainly.com/question/2952156