K in the Cobb Douglas function I'm using the Cobb Douglas production function for a Mathematics investigation into how optimisation works in Economics. The assumption is that the firm require's only one type of capital, that is, a coffee machine. Keeping this in mind, would it be reasonable to take K as the number of coffee machines  used, instead of hours?
Thanks, and cheers!
There is no "reasonable" choice here.

One can choose inches over centimeters, gallons of water over kilograms of water, etc. This depends on how you want measure the input quantities. No choice is wrong so long as it is consistent with your other modelling choices.