It is the pre lab working "Charge to mass ratio of the electron" (e/m) and this section is about the Helmholtz Coils. Please help me do these question. Thanks so much in advance.

Question 7: What is an expression for the magnitude of the net force acting on an object of mass m moving in a circle of radius r at constant speed 1;? Question 8: Assuming that the magnetic eld strength between the coils is B, what is the magnitude of the magnetic force acting on an electron moving with speed '0? Question 9: Use your previous two answers to express 7" in terms of U, B, and e / m. In class you saw that the magnetic eld strength B a distance 2 along the axis of a coil of N loops of current I and radius R (don't get this confused with the electron path radius r) is given by some? B: . 2(R2+z2)3/2 Helmholtz coils are in a conguration such that there are two separate coils to consider (as considered in Question 4), and each coil is located at a distance 2 = R/2 from the midpoint. Question 10: Use the above expression to derive a relationship between the current in the TWO coils (of N loops each) and the magnetic eld strength at the halfway point between them. Simplify your answer as much as you can: Question 11: What are the two variables in Question 9 that affect the radius of the electron path T and how can each be varied? Question 12: Combine your answers from Questions 2 and 9 to nd an expression relating e/m, r2, B2, and AV, thereby eliminating the electron gun exit speed 1)