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In question ten, you indicated "vertically upward"in regards to the magnetic field as coming out of the page. But in this problem, you indicated the "vertically upward" velocity as north/upward on the page.

Which way should I understand the term?

Hi prologue,

"Vertically upward" means North, or upward on the page. If I said otherwise with the magnetic field, then I misspoke there. When something is coming out of the page, I usually say exactly that, or I say directed "towards you".

Best wishes,
Mr. Dychko

EDIT: now I took a peek at #10 (should have done that before the original reply!)

"vertically upward" has a meaning which depends on context. If you're standing outside, vertically upward means toward the sky (not North), and this is the meaning in #10. Otherwise, if you're looking at a 2D page, vertically upward normally means North, unless something in the wording of the question suggests otherwise.

No matter which way you look at it, context is important, and I wonder if students in the Southern hemisphere regard "upward" as being South? (I think they probably still view "up" as North since maps are printed with the North Pole at the top, but there's no rule against making a map with the South Pole at the top, in which case "up" would be South....) Even suggesting that vertically upward is toward the sky is ambiguous if you want to get silly about it: toward the sky for North Americans is toward the ground for Australians on the opposite side of the Earth, and I suppose you'd have to say that "vertically upward" is "opposite the direction of gravity"... but I digress...