The Electromagnetic spectrum.
Answer:
Speed = 3 [km/h]
Explanation:
To solve this problem we must use the definition of speed which relates the distance traveled for a while.
Distance = 1.5 [km] = 1500 [m].
time = 0.5 [hr] = 1800 [s]
Speed = Distance/time
Speed = 1.5/0.5
Speed = 3 [km/h] or 1500/1800 = 0.8333[m/s]
There's no such thing as "stationary in space". But if the distance
between the Earth and some stars is not changing, then (A) w<span>avelengths
measured here would match the actual wavelengths emitted from these
stars. </span><span>
</span><span>If a star is moving toward us in space, then (A) Wavelengths measured
would be shorter than the actual wavelengths emitted from that star.
</span>In order to decide what's actually happening, and how that star is moving,
the trick is: How do we know the actual wavelengths the star emitted ?
For an uniformly accelerated motion, we can write
where
is the acceleration of this motion, which in this problem is the gravitational acceleration, with a negative sign because it points downward, against the direction of the motion; h=0.540 m is the distance covered by the flea, and
is the initial velocity.
At the maximum height, the velocity is zero, so
. Therefore we can solve to find
:
