Calculating friction in Parallel?

[davidc95]

Hi,

For a school project I have created a system which applies an equal force to 4 objects of measurable friction. Each yields a frictional force of approx. 3N (calculated from F = μF_Normal) when in motion - but I am not quite sure as to calculating the total frictional force the combined set of 4 generates 'together' against the system supplying the same applied force across all of them.
Is it as simple as adding the 4 frictional forces together? Or perhaps more complex, through employing the parallel equation of (1/F_Total) = (1/F) + (1/F) + (1/F) + (1/F), for example? Or maybe its something different?

Thanks in advance for any help.

 

[CWatters]

If they are all acting in the same direction just add them together. If they act in different directions or at different angles you need use vector addition.