What are the first four resonant frequencies of a 10-cm long tube with (a) both ends open? (b) both ends closed? (c) one end open and one end closed?

Aprotein molecule in an electrophoresis gel has a negative charge. the exact charge depends on the ph of the solution, but 30 excess electrons is typical. what is the magnitude of the electric force on a protein with this charge in a 1600n/c electric field? write in two significant numbers, and also in newton