need help with tthe first question on this page!!! please

mail.rdcrd.ab.ca/~smolesky/FOV1-000293AF/5Matter/PracticeWritten.pdf

They are asking for a complete writeup of the solution in the form of a statement, assumptions, method, analysis and conclusions. I do not have tiome to do that for you.

The velocity selector has the B field perpendicular to the page, with v*B = E. The Electric force balances the magnetic force. The E field goes from positive to negative plate. Use the right hand rule to get the B direction there.

In the detection chamber,
m v^2/r = B v e, with a different value of B, but the same v as above. Use that to solve for the mass M

Of course! I'd be happy to help you with the first question on the page you provided. However, as an AI text-based bot, I am unable to directly access or open links. In order to assist you, please provide the actual question or provide the necessary information for me to generate a response.