Where to Place a Fiducial Marker in SHM Systems?

[Rohan1997]

Homework Statement

Where would be the perfect place to place a fiducial marker in a: mass on a spring system (vertical) and a simple pendulum?

Homework Equations

The Attempt at a Solution

My teacher told me that for a simple pendulum it would be below the bob at equillibrium position because this is the point where the bob has its max. speed or the transit time is the smallest

But I have no idea why this would mean that the below the bob would be better then anywhere else

 

[paisiello2]

Wouldn't it interfere if it was placed anywhere else?

 

[sophiecentaur]

If you put the mark right below the suspension point, there would be virtually no movement at all. If you want to maximise the movement, you need to be near (even beyond) the bob.