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3 questions..please help (1 Viewer)
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rama_v
Active Member
11. just use E = hf = hc/l where l is wavelength
so E = (6.626 x 10-34)(3x108) / (20 x 10-9)
so E = (6.626 x 10-34)(3x108) / (20 x 10-9)
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rama_v
Active Member
For the second one its clear from the graph that the spacecraft would want to send signals that can have the best possibility of travelling through the atmosphere and down to the ground where the signals can be picked up by a large satellite dish. What you need to do is convert the MHz to Wavelength. Again use the formula c = fl where l is wavelength. Rearranging, you get:
Wavelength = c / f = (3 x 108) / (2295 x 106) because the frequency is in MegaHertz (need to convert to Hertz).
therefore wavelength = 1.31 x 10-1 m
When looking at the graph, we can see that the transmission of this frequency (i.e. wavelength) is very high (about 95%), so it would be suitable for use as there is a great possibility that the signals will reach earth.
Im pretty sure the first one is not part of the sylabus
Wavelength = c / f = (3 x 108) / (2295 x 106) because the frequency is in MegaHertz (need to convert to Hertz).
therefore wavelength = 1.31 x 10-1 m
When looking at the graph, we can see that the transmission of this frequency (i.e. wavelength) is very high (about 95%), so it would be suitable for use as there is a great possibility that the signals will reach earth.
Im pretty sure the first one is not part of the sylabus
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just an extra note
although this thread is full of my own comments.. i must add..
for Q16: is it even in the syllabus? i dont recall having done any experiment of that sort. AND it reminds me of circular motion....
although this thread is full of my own comments.. i must add..
for Q16: is it even in the syllabus? i dont recall having done any experiment of that sort. AND it reminds me of circular motion....
Captain Gh3y
Rhinorhondothackasaurus
Both of the second 2 questions are from dotpoints that were removed after 2002. (circular motion, communication with satellites) You can still do the 2nd one though.
Hmm... 2pi*r/T is just diameter/period or distance/time, but that's been taken out. (Now if you ever see a question about the orbital velocity of a satellite you have to use centripetal force = gravitational force and solve for v)
Hmm... 2pi*r/T is just diameter/period or distance/time, but that's been taken out. (Now if you ever see a question about the orbital velocity of a satellite you have to use centripetal force = gravitational force and solve for v)
rama_v
Active Member
Yeah..but its good to know v = 2pir/T because thats where Kepler's Law is derived fromCaptain Gh3y said: