Why Might Forces and Torques Not Sum to Zero in a Static Equilibrium Lab?

[mrbiggstuff44]

In a static equililibrium lab, what are some reasons why the sums of the forces and/or torques may not be equal to zero. The forces in N are very close to zero (as my professor said they should be) and the torques in N-cm are not anywhere close to zero. I know the torques are greater than their corresponding forces due to the fact they are being multiplied by a distance r as well as the sin of ∅. My professor told me that I would not get zero for either calculation, and therefore would need to tell him why the corresponding values do not sum to zero.

Thanks

 

[Valerie Park]

for your question! There are several reasons why the sums of the forces and/or torques may not be equal to zero in a static equilibrium lab. One reason is that the system may be subject to external forces or torques (e.g. gravity, air resistance). Another reason is that the system may contain components that are not in perfect alignment, resulting in non-zero torques due to misalignment. Finally, errors in measurements can also lead to non-zero sums of forces and/or torques.