Answer:
Their speed in a vacuum is a constant value.
Explanation:
Electromagnetic waves consits of oscillations of electric field and magnetic field. The oscillations of these fields occur in a direction perpendicular to the direction of propagation of the waves, so they are transverse wave. Electromagnetic waves, contrary to mechanical waves, do not need a medium to propagate, so they can also travel through a vacuum. In a vacuum, their speed is constant and has always the same value, the speed of light:

Answer: W represents an element Y represents a mixture
Explanation: I just took a quiz on this and got it right. Good Luck
Answer:
I need to talk to somone about my confusing love life
Explanation:
<span>During the December solstice the declination of the Sun is at 23.5° South of the equator. During the December solstice, locations in the Northern Hemisphere experience their shortest day. The December solstice is also the first day of winter in the Northern Hemisphere. Locations in the Southern Hemisphere have their longest day on the June solstice. This date also marks the first day of summer in the Southern Hemisphere.
During the June solstice the declination of the Sun is at 23.5° North of the equator. During the June solstice, locations in the Northern Hemisphere experience their longest day. The June solstice is also the first day of summer in the Northern Hemisphere. Locations in the Southern Hemisphere have their shortest day on the June solstice. This date also marks the first day of winter in the Southern Hemisphere.</span>