Question

I need help with this please. Quick.
-Attached

Answer 1

hi
are you still there?

Answer 2

so 3000 turns/min = 500 turns / second.
So each turn takes 1/500 s or 2 micro second. So each turn is given by a short pulse in a 2 micro second period.

Answer 3

If you put the scale to 100 micro seconds you'll get 50 pulses in 1 cm of the display which is not very clear so you have to put it on 1us/cm so that each in total you get 5 pulses on the screen.

Answer 4

But the answer is 10 ms/cm. :O

Answer 5

wait a second let me check again.

Answer 6

Ok.

Answer 7

ooops sorry I got the numbers wrong
3000 revs/min=50 revs/sec

Answer 8

so one turn in 1/50=.02s

Answer 9

It's fine. So what do I do next?

Answer 10

so each pulse is 20 ms so if you put the dial on 10 ms/cm

Answer 11

then you get a clear readin of the pulses
sorry about the mistake at the begining

Answer 12

so each pulse falls within 2cm of the display so you get 5 nice discinct pulses

Answer 13

makes sense?

Answer 14

Yes, it does. Thank you so much! :)

Answer 15

no problem !