VINNANDE VETANDE - Svenska Fysikersamfundet

cylindrisk homogen stång som är 8,0 m lång och väger 85 kg. Figur med
kraftanalys erfordras.
4. Uppskatta till vilket tryck man kan pumpa upp en cykelslang med en
vanlig cykelpump.
5. The following exchange of correspondance took place between the agent
of a computer company and a student.
Dear Madam/Sir,
The pattern on the
video monitor (screen)
of the computer I
bought from your
company is, to my
annoyance, not
centered on the screen
but is displaced by 3
mm to the right, as
indicated in the sketch.
Please advice how this may
Dear Student,
The cathode ray system in your
computer was aligned in California
where the magnetic field of Earth
has the same magnitude as in New
Zealand (55 µT) but is pointed
"down" as shown, rather than "up"
as in New Zealand.
The computer is not magnetically
shielded; it is therefore sensitive to any
change in the (vertical) component of the
field. This will deflect the 12 kV electron
beam in the 15 cm from the gun to the
screen. Your local dealer can correct this
by an internal adjustment. For safety
reasons do not attempt this yourself.
Si l
Confırm the explanation by calculating the beam deflection. To do this,
focus your attention on the electrons in the electron beam, when centrally
positioned, and assume that the change in velocity direction is small.
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