The Russell Traction System To immobilize a fractured femur (the thigh bone), doctors often utilize the Russell traction system illustrated in the figure. Notice that one force is applied directly to the knee, F_1,while two other forces, F_2 and F_3 are applied to the foot. The latter two forces combine to give a force F_2 + F_3 that is transmitted through the lower leg to the knee. The result is that the knee experiences the total force F_{total} = F_1 + F_2 + F_3. The goal of this traction system is to have F_{total} directly in line with the fractured femur, at an angle of 20.0 above the horizontal.

Question

The Russell Traction System To immobilize a fractured femur (the thigh bone), doctors often utilize the Russell traction system illustrated in the figure. Notice that one force is applied directly to the knee, F_1,while two other forces, F_2 and F_3 are applied to the foot. The latter two forces combine to give a force F_2 + F_3 that is transmitted through the lower leg to the knee. The result is that the knee experiences the total force F_{total} = F_1 + F_2 + F_3. The goal of this traction system is to have F_{total} directly in line with the fractured femur, at an angle of 20.0 above the horizontal.

1. Find the angle \theta required to produce this alignment of F_{total}. (Assume the pulleys are ideal.)

2. Find the magnitude of the force, F_{total} that is applied to the femur in this case.

I tried tutoring with both these questions and even they could not help me. I really hope and pray Jiska can.

Answer 1

For the angle you have to add all angles, so u get 60 degrees. I am not sure about the Ftotal.

Hope this helps!

Answer 2

Jenny are there any numbers for forces?

Answer 3

I not sure if this can be answered =-(

Answer 4

This is an image I found, but it does not fit the description.

http://3.bp.blogspot.com/_-WsaCfPPjYQ/SIqbam3U7QI/AAAAAAAAAtI/JV4ysqn2BPQ/s320/pelvic_belt_traction.jpg
Can you describe the figure that we don't see?

Answer 5

To determine the angle and magnitude of the total force applied to the femur in the Russell traction system, we need to analyze the forces involved and their components.

1. Finding the angle θ:
In the system described, the total force F_total is applied at an angle of 20.0° above the horizontal. Let's represent this angle as θ.

Since F_total is the sum of three individual forces, we need to determine the angles of those forces first.

Force F_1 is applied directly to the knee, so it is vertical and has an angle of 90°.

Forces F_2 and F_3 are applied to the foot. As they combine to give F_2 + F_3 transmitted through the lower leg to the knee, we can assume that F_2 and F_3 have the same magnitude and are equal in value.

Now, let's consider the equilibrium of forces in the vertical direction. We have F_total acting upwards and F_1 acting downwards. Since there is no vertical movement, these two forces must cancel each other out.

Therefore, we can set up a vertical force equilibrium equation:
F_total * sin(θ) = F_1 * sin(90°) + (F_2 + F_3) * sin(180°)

Since sin(90°) = 1 and sin(180°) = 0, the equation simplifies to:
F_total * sin(θ) = F_1 + F_2 + F_3

Now, we know that F_total has an angle of 20.0° above the horizontal. Therefore, we can rewrite the equation as:
F_total * sin(20.0°) = F_1 + F_2 + F_3

From this equation, you can solve for the angle θ.

2. Finding the magnitude of F_total:
To find the magnitude of F_total, we need to consider the forces in the horizontal direction.

In equilibrium, the horizontal forces must balance each other out. So, let's set up a horizontal force equilibrium equation:
F_total * cos(20.0°) = (F_2 + F_3) * cos(180°)

Since cos(180°) = -1, the equation simplifies to:
F_total * cos(20.0°) = -(F_2 + F_3)

From this equation, you can solve for the magnitude of F_total.

Note: It's essential to know the values of F_1, F_2, and F_3 to calculate the magnitude of F_total accurately.