Answer:
Go to Insert and click on Text and underneth that click header and footor.
Explanation:
You can do a Header and Fotter in Excel. ALl you have to do if go in the document you are working in and you click on Instert tab and then click on Header and Fotter. It gives you an option to make a header for your excel wookbook.
Answer:
Basically, anything quantity that is not defined as one of the 7 base quantities is a derived quantity by definition. Pressure is not one of the 7 base quantities. Hence it is a derived quantity.
You use the extension on the end of the file to tell you the type of a file
The extension is the .whatever in the name of the file
