Light is a form of energy.
(:
Explanation:
Only few supernova are observed in our galaxy -
Type II supernovae ( i.e. the explosions of the massive stars ) occurred in the Milky Way, and they might be hidden by the intervening dust if they are located in the more distant parts of our Galaxy .
Type Ia supernovae , which need a white dwarf star in the binary star system , are brighter than the type II supernovae , but some of them could also happen in the older parts of Galaxy which are hidden due to the buildup of the dust and gas .
First choice: the inability of current technology to capture
large amounts of the
Sun's energy
Well, it's true that large amounts of it get away ... our 'efficiency' at capturing it is still rather low. But the amount of free energy we're able to capture is still huge and significant, so this isn't really a major problem.
Second choice: the inability of current technology to store
captured solar
energy
No. We're pretty good at building batteries to store small amounts, or raising water to store large amounts. Storage could be better and cheaper than it is, but we can store huge amounts of captured solar energy right now, so this isn't a major problem either.
Third choice: inconsistencies in the availability of the resource
I think this is it. If we come to depend on solar energy, then we're
expectedly out of luck at night, and we may unexpectedly be out
of luck during long periods of overcast skies.
Fourth choice: lack of
demand for solar energy
If there is a lack of demand, it's purely a result of willful manipulation
of the market by those whose interests are hurt by solar energy.
Answer:
0.657 seconds
Explanation:
speed of wave= wavelength / time period
so
time period= wavelength / speed
= 4.6/7
=0.657 sec
