EASY
AS and A Level
IMPORTANT
Earn 100
Neptune is the farthest known planet from the Sun in the Solar System. Its distance from the Sun is 30 times greater than the distance of the Earth from the Sun. The radiant flux intensity from the Sun at the Earth is .
A space probe is close to Neptune.
Calculate the maximum radiant power received by an instrument of cross-sectional area on this space probe.
Important Questions on Astronomy and Cosmology
EASY
AS and A Level
IMPORTANT
Establish the knowledge of electromagnetic waves, including spectra, would be valuable in the understanding of this chapter.
EASY
AS and A Level
IMPORTANT
Can you recall intensity of a wave and its units?
EASY
AS and A Level
IMPORTANT
The idea of the Doppler effect of sound will be extended to spectra from distant stars. When is the observed wavelength shorter, or longer?
EASY
AS and A Level
IMPORTANT
State two factors that affect radiant flux intensity from a star.
EASY
AS and A Level
IMPORTANT
The radiant flux intensity F of light from a lamp at a distance of is . Calculate F from the same lamp at a distance of . State any assumption(s) you make.
EASY
AS and A Level
IMPORTANT
Use data from Table to determine, to two significant figures:
(a) the distance of Sirius from the Earth in metres.
EASY
AS and A Level
IMPORTANT
Use data from Table to determine to two significant figures the luminosity (in W) of Canopus.
EASY
AS and A Level
IMPORTANT
Use data from Table to determine, to two significant figures the luminosity (in W) of Vega.
