Probably for kind of the same reason that speed is expressed as a
relationship between two units. You know, like miles per hour .
I guess the only reason is because no single unit has been invented
to describe density.
The rate of doing work or using energy would always be expressed
as a relationship between two units ... we would say that the rate of
work is "(so many) joules per second". But the "watt" was invented,
so we can say "(so many) watts" instead.
So I guess you're right. Density could be simpler to describe
if we only had a unit for it. Then we wouldn't have to say "(so many)
grams per cubic centimeter". We would just say "(so many) (new unit)".
Let's try it out:
"Uhhh, pardon me Professor . . . I've been working late in the lab,
and I believe I've identified a new substance, hitherto unknown to
the scientific community, and totally unexpected. In its pure form,
the substance appears to be pink, it smells like butterscotch, and
its density is approximately 27.4 Brianas. I think it's time we published
these findings ... with your name as lead investigator, of course."
I like it !
Answer:
a) 42 m/s, positive direction (to the east), b) 42 m/s, negative direction (to the west).
Explanation:
a) Let consider that Car A is moving at positive direction. Then, the relative velocity of Car A as seen by the driver of Car B is:

42 m/s, positive direction (to the east).
b) The relative velocity of Car B as seen by the drive of Car A is:

42 m/s, negative direction (to the west).
Answer:
Energy production requires the setting up of a complete interconnected chain from generation of energy from the root source of the energy to the storage of the generated energy and the eventual utilization of the energy when required
Solar energy, indirectly, continues to be the main source of energy, however, the direct use of solar energy to power the systems we use in our everyday life, require the development of technologies, such as high efficiency solar cells, means of energy storage, and compatible efficient energy usage which are industrial areas that are seeing good progress but in which the current developed equipment are expensive to produce, and due to their efficiency, are undergoing further research and development
Therefore, due to the continuous increasing improvement in solar technology which can observed, the use of the produced energy through solar is evolving, and therefore, will continue to play a continuously increasing but lower role compared to other sources of energy which have been developed to satisfactory level that can drive an industry, considering the financial investment involved
Explanation:
When conducting and experiment you want to have a notebook and something to write down notes with so you can keep everything organized and proper, and to not miss anything in the experiment. Also you want to have everything in order of the way it should be in.
I hope you found this helpful!
Answer:
= 5.1 W
Explanation:
time (t) = 30 ms = 0.03 s
mass (m) = 560 g = 0.56 kg
initial velocity (U) = 0 m/s
final velocity (V) = 0.74 m/s
power = \frac{work done}{t} = \frac{f x d}{t} = f x v = m x a x v
m x a x v = m x \frac{V-U}{t} x \frac{V + U}{2}
m x \frac{V-U}{t} x \frac{V + U}{2} = 0.56 x \frac{0.74 - 0}{0.03} x \frac{0.74+0}{2}
= 5.1 W