What kind of thermal radiation does the earth emit?

Plss anybody know how to do this? ? i need the answers from a through d

Aprotein molecule in an electrophoresis gel has a negative charge.the exact charge depends on the ph of the solution, but 30 excesselectrons is typical. what is the magnitude of the electric forceon a protein with this charge in a 1500 n/c electric field?

How do i solve this physics problem?