Well, first of all, EVERY physical quantity is measured in a combination
of 2 or more units, except for mass, length, time, and electric charge.
ALL other units are made out of these. So it should not surprise you.
[ Example: Speed = (length) / (time) ]
Density is not the mass of a substance. It's the mass of a substance in
a standard volume of it. So the density is made of the mass in any lump
and the volume of that lump. That way, no matter how much of a substance
you have, you can always compare the lump you have to all other substances.
Answer:
it will stay still. unless its in space.
Explanation:
Efficiency = 1000/2000 = 0.5 = 50%
Answer:
The star is moving toward us
Explanation:
The wavelength of a distant object changes due to the change in the distance between the observer and the object. This is known as the Doppler effect.
If the wavelength decreases this means that the wavelength in going towards blue which is shorter wavelength. This is known as blue shift. If blue shift occurs then it means that the object is coming closer to the observer.
Hence, the star described here has blue shifted and is moving closer to us.
