How can i use Case with manipulate parameters?

Questions
1

I try to use “manipulate”, changing the same parameters (in this case f as friction), but this parameters has to have different values in four cases.

2

Hi,

are you looking for something like this:

Manipulate[Plot[Sin[a t], {t, 0, 12}], {a, {1, 2, 3, 4}}, ControlType -> PopupMenu]

ManipulateCases.gif

Cheers,

Marco