Question

how to figure the distance between troughs?

If one is at 10cm and the other is at 30cm

Answer 1

To figure the distance between two troughs, you simply need to subtract the position of the first trough from the position of the second trough.

In your case:

1. Position of the first trough = 10 cm
2. Position of the second trough = 30 cm

Distance between the troughs = Position of the second trough - Position of the first trough
Distance = 30 cm - 10 cm = 20 cm

So, the distance between the two troughs is 20 cm.