<span>Four waste materials from copper ore processing are: ore minerals, unwanted rock or gangue, uranium, and pyrite/sulfide minerals. Ore minerals are contained in rock and have potential to be economically extracted, gangue may contain silicate minerals for which there is no economic value, uranium is a frequently-occurring radionuclide found in ore bodies, and pyrite and sulfide minerals may be found in tailings piles during copper processing.</span>
This really calls for a blackboard and a hunk of chalk, but
I'm going to try and do without.
If you want to understand what's going on, then PLEASE
keep drawing visible as you go through this answer, either
on the paper or else on a separate screen.
The energy dissipated by the circuit is the energy delivered by
the battery. We'd know what that is if we knew I₁ . Everything that
flows in this circuit has to go through R₁ , so let's find I₁ first.
-- R₃ and R₄ in series make 6Ω.
-- That 6Ω in parallel with R₂ makes 3Ω.
-- That 3Ω in series with R₁ makes 10Ω across the battery.
-- I₁ is 10volts/10Ω = 1 Ampere.
-- R1: 1 ampere through 7Ω ... V₁ = I₁ · R₁ = 7 volts .
-- The battery is 10 volts.
7 of the 10 appear across R₁ .
So the other 3 volts appear across all the business at the bottom.
-- R₂: 3 volts across it = V₂.
Current through it is I₂ = V₂/R₂ = 3volts/6Ω = 1/2 Amp.
-- R3 + R4: 6Ω in the series combination
3 volts across it
Current through it is I = V₂/R = 3volts/6Ω = 1/2 Ampere
-- Remember that the current is the same at every point in
a series circuit. I₃ and I₄ must be the same 1/2 Ampere,
because there's no place in the branch where electrons can
be temporarily stored, no place for them to leak out, and no
supply of additional electrons.
-- R₃: 1/2 Ampere through it = I₃ .
1/2 Ampere through 2Ω ... V₃ = I₃ · R₃ = 1 volt
-- R₄: 1/2 Ampere through it = I₄
1/2 Ampere through 4Ω ... V₄ = I₄ · R₄ = 2 volts
Notice that I₂ is 1/2 Amp, and (I₃ , I₄) is also 1/2 Amp.
So the sum of currents through the two horizontal branches is 1 Amp,
which exactly matches I₁ coming down the side, just as it should.
That means that at the left side, at the point where R₁, R₂, and R₃ all
meet, the amount of current flowing into that point is the same as the
amount flowing out ... electrons are not piling up there.
Concerning energy, we could go through and calculate the energy
dissipated by each resistor and then addum up. But why bother ?
The energy dissipated by the resistors has to come from the battery,
so we only need to calculate how much the battery is supplying, and
we'll have it.
The power supplied by the battery = (voltage) · (current)
= (10 volts) · (1 Amp) = 10 watts .
"Watt" means "joule per second".
The resistors are dissipating 10 joules per second,
and the joules are coming from the battery.
(30 minutes) · (60 sec/minute) = 1,800 seconds
(10 joules/second) · (1,800 seconds) = 18,000 joules in 30 min
The power (joules per second) dissipated by each individual resistor is
P = V² / R
or
P = I² · R ,
whichever one you prefer. They're both true.
If you go through the 4 resistors, calculate each one, and addum up, you'll
come out with the same 10 watts / 18,000 joules total.
They're not asking for that. But if you did it and you actually got the same
numbers as the battery is supplying, that would be a really nice confirmation
that all of your voltages and currents are correct.
We want to find the energy that we need to transform 2kg of ice at 0°C to water at 20°C.
We will find that we must give 840,000 Joules.
First, we must change of phase from ice to water.
We use the specific latent heat of fusion to do this, this quantity tells us the amount of energy that we need to transform 1 kg of ice into water.
So we need 336,000 J of energy to transform 1kg of ice into water, and there are 2kg of ice, then we need twice that amount of energy:
2*336,000 J = 672,000 J
Now we have 2kg of water at 0°C, and we need to increase its temperature to 20°C.
Here we use the specific heat, it tell us the amount of energy that we need to increase the temperature per mass of water by 1°C.
We know that:
specific heat of capacity of water = 4200 J/kg°C
This means that we need to give 4,200 Joules of energy to increase the temperature by 1°C of 1kg of water.
Then to increase 1°C of 2kg of water we need twice that amount:
2*4,200 J = 8,400 J
And that is for 1°C, we need to give that amount 20 times (to increase 20°C) this is:
20*8,400 J = 168,000 J
Then the total amount of energy that we must give is:
E = 672,000 J + 168,000 J = 840,000 J
If you want to learn more, you can read:
brainly.com/question/12474790
Since each serves a different purpose, theories cannot become
laws. Explaining how or why a natural phenomenon occurs is what the set of ideas
called theories do. On the other hand, mathematical relationships that
describes what happens are what is done by laws.
Let me show an example that illustrates the points.
Describing what happens in the natural world are done by the mathematical
formulas called the Gas Laws. In this example, it would show that by using the
Gas Laws, I will be able to predict with great accuracy the pressure if I
double the temperature of a sealed gas. This idea is a law since the
relationship is mathematical and it tells us what will happen.
<span>On the other hand, in order to explain why gases behave like
the way they do, we must use the kinetic molecular theory.</span>
