Answer:
(D) the sphere
Explanation:
The bodies given are Disk and Solid sphere (uniform sphere)
Moment of inertia of the bodies are
I(disk) =
I(sphere) =
Since the moment of inertia of sphere is less than that of disk, therefore sphere will reach the bottom first.
Well, that's easy to answer when we realize that "First Quarter" isn't talking about a 'quarter' of the Moon being illuminated. It's talking about a 'quarter' of the time that the complete cycle of phases takes.
"First quarter" means that 1/4 of the time from one New Moon to the next one has passed, and there are 3/4 of the cycle left until the next New Moon.
-- roughly 3/4 of a month to go
-- roughly 3 weeks to go
-- actually 3/4 of (29.531 days)
-- actually 22 days 3.6 hours until the instant of the next New Moon.
But Haley doesn't actually need to wait that long. You can't see the moon in the sky for 1-2 days before the New Moon and 1-2 days after it. So Haley really only has to wait like 20 days until there's no moon in the sky to interfere with her observations.
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Did you notice what I noticed ?
What if Haley stays interested in Astronomy for many years, gets really serious about doing observations regularly, and one day she discovers a comet ! These days, comets are named for their discoverers, so if that happened, we would have TWO of um !
Answer:
Assume that this wavelength is measured in vacuum. The energy on each photon of this wave would be approximately .
Explanation:
The Planck-Einstein Relation relates the energy of a photon to its frequency :
,
where is Planck's Constant.
.
This question did not provide the frequency of this wave directly; the value of needs to be calculated from the wavelength of this wave. Assume that this wave is travelling at the speed of light in vacuum:
.
The frequency of this electromagnetic wave would be:
.
Apply the Planck-Einstein Relation to find the energy of a photon of this electromagnetic wave:
.
Note that combining the two equations above ( and ) will give:
.
This equation is supposed to give the same result (energy of a photon of this wave given its wavelength and speed) in one step:
.