A uniform meter rule of mass 100g balance at a 40cm mark when a mass x is placed at the 10cm mark. what will the value of x ​

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