Solving Torque in Stretcher/Paramedic Problem-Unsure About Fulcrum

[katieoneill]

Hello,

I've seen a similar problem posted here but the answer to my question was not included. The details of my problem are not so important as I do not require a solution, just help in one aspect of the problem: finding the fulcrum in order to calculate torques to balance each other (in order to find the forces contributed by either side).

The problem is 2 paramedics carrying a stretcher with some body of some mass with a center of gravity closer to one paramedic. I was unsure of where the fulcrum would be in order to calculate torque. I did the problem by calculating the torque for paramedic A using the fulcrum as paramedic B and vice versa, but I have no idea if this is correct. It seems odd to use 2 fulcrums in a problem, but it seems to me when I visualize the problem that the pivot point for each side is the other side.

Can anyone please help me with this? Also, is there a standard rule of thumb for finding the fulcrum in problems where it is not obvious (obvious like a seesaw or wrench).

THANK YOU!

 

[gsal]

Well, if you take paramedic A as fulcrum and calculate the force for paramedic B; and then you take paramedic B as fulcrum and calculate the force for paramedic A...do they both add up to the weight of the body? In other words, you solved for the forces knowing the the stretcher is not rotating, fine; now, you can use the static equation (the stretcher is not moving up or down, either) to verify that the forces from the paramedics equal the force down from the body. If so, you have solve the problem correctly.