There are no rules that describe how positive energy behaves
in the presence of negative energy, because there is no such
thing as negative energy.
(Wellll ... in pop Psychology, perhaps, but not in any real science.)
Answer:
, ,
Explanation:
Let assume that steam has a fully developed and turbulent flow and that tube is smooth and thin-walled. The steam is heated while flowing through the tube. The Nusselt number is given by the Dittus-Boelter equation:
Properties of steam at given pressure and temperature are:
The Reynolds and Prandtl numbers are, respectively:
(which demonstrates the reasonability of the supposition of turbulent flow)
The Nusselt number is:
The Nusselt number has the following definition:
The heat transfer coefficient is:
The convection is the dominant heat transfer mechanism, then:
Answer:
6.33 km/s
Explanation:
Given that :
A spaceprobe in outer space is flying with a constant speed = 1.530 km/s.
The probe has a payload = 1363.0 kg
which carries 3486.0 kg of rocket fuel.
Exhaust speed = 3.795 km/s
How fast will the spaceprobe travel when all the rocket fuel is used up?
As we know that the rate of change of spaceprobe momentum is equal to the thrust of the rocket.
Then;
where;
= exhaust speed
Taking the integral of the above expression; we have:
= 6.33 km/s
Answer:
when there is no water in the atmosphere or when no drops are formed there is no rainbow..
he hydrogen transition lines would be missing in the visible range, the RED region
Explanation:
The sunlight that reaches the Earth is scattered by the atmosphere and radiated, as the atmosphere has mainly nitrogen, the radiated light is blue, this light does not produce a rainbow.
The sunlight must reach a drop of water that disperses the colors according to the refractive index of the water and in this way produces a rainbow, so when there is no water in the atmosphere or when no drops are formed there is no rainbow..
If the atmosphere were composed of Hydrogen, the hydrogen transition lines would be missing in the visible range, this corresponds to the so-called Balmer series and they are in the RED light region.