Do you hang up a cellphone?

Solution 1:

Yes, one can.

Of course, it is applying a term that no longer has the direct meaning that it once did, but then teamsters no longer control a team of horses, core-dumps no longer have anything to do with ferrite cores, salaries are no longer paid in salt, and most people don't look at the stars when they consider something.

As such, it is one of a great many terms that relate to an historical artefact that is no longer relevant to the modern use.

For that matter, we still call them phones, when most that you can buy today are not actually phones, but rather multi-purpose pocket-sized computers that have a phone application among a great many others.

Solution 2:

Yes, you do. You can disconnect or hang up.

Even though we do not literally hang up the phone anymore, hang up has become idiomatic fro "disconnect the telephone connection".

This is not something new from the age of the mobile phone, even with a lot of "home phones" you have not been "hanging up" in the literal sense for a very long time.

On old telephones, you had to hang the "handset", rather the speaker part, back on a hook on the telephone. That hook would act as a switch to disconnect.

Compare it to to dial a number: we have not been dialling numbers in the literal sense for ages, the expression stems from the days when telephones had a dial that you would have to turn to form the number.

When we started effectively typing the number, we still called it dialling.