How to divide a line into several equal segments?

I’d suggest looking at these two tools:

1. Grid Array Tool - This will allow you to create copies of a shape in various ways with a tremendous amount of flexibility
2. Arrange->Distribute - This will allow you to distribute existing shapes evenly. If you position the two pieces at the extremes of the area you want covered this tool will distribute all the shapes evenly between those extremes

This is my first thought:

1. Draw a ‘cutting’ line and place it at one end of the line you want divided.
2. Select your cutting line first then select the line you want divided using either shift-click or ctrl-click so that you have both lines selected (the selection order is important!).
3. Use the ‘Copy Along Path’ tool to copy your cutting line as many times as you need.

4. Then use the ‘node edit’ tool to place nodes at the intersections of you main line and your cutting lines.

5. Lastly, delete your cutting lines.