(a) 
The relationship between frequency and wavelength of an electromagnetic wave is given by
where
is the speed of light
is the frequency
is the wavelength
In this problem, we are considering light with wavelength of
Substituting into the equation and re-arranging it, we can find the corresponding frequency:
(b) 
The period of a wave is equal to the reciprocal of the frequency:
And using 
as we found in the previous part, we can find the period of this wave:
It has to move through a distance over time.
Answer:
truck 1 has the most velocity
Explanation:
Because it weights less which means it faster and yea
If Earth's axis was "straight up and down" instead of tilted, then ...
<span>-- There would be no seasons.
-- The climate at any one place would be the same all year around.
-- The days would be the same length, everywhere,
and all year around.
-- So would the nights.
-- The sun would be up a little more than 12 hours every day.
It would be down a little less than 12 hours every day.
-- At the middle of the day, the sun would be at the same height
in the sky all year around, not higher in some months and lower
in others.
-- The equator would be the only place on Earth where the sun
could ever be directly over your head.
-- If you were at the north pole or the south pole, the sun would be
down on the horizon, and it would just go around and around you
every day. It would never rise or set, and it would never get any
higher or lower.
</span>
