<span>The core finally cools into a white dwarf, then a black dwarf. This is what happens when a normal-sized star dies. If a really huge star dies, it has so much mass that after the helium is used up, it still has enough carbon to fuse it into heavy elements like iron. When the core turns to iron, it no longer burns.
please give me </span>Brainliest answer?
I = E / R
If the resistors are in series, the current is 0.3 Amperes.
If the resistors are in parallel, the current is 1.25 Amperes.
Answer:
Frequency – The frequency of a wave is the number of waves that pass a given point in a certain amount of time. Frequency is measured in units called hertz (Hz), and is defined as the number of waves per second. A wave that occurs every second has a frequency of 1 wave per second (1/s) or 1 Hz.
efficiency = (useful energy transferred ÷ energy supplied) × 100
It's easy to use this formula, but we have to know both the useful energy and the energy supplied. The drawing doesn't tell us the useful energy, so we have to find a clever way to figure it out. I see two ways to do it:
<u>Way #1:</u>
We all know about the law of conservation of energy. So we know that the total energy coming out must be 250J, because that's how much energy is going in. The wasted energy is 75J, so the rest of the 250J must be the useful energy . . . (250J - 75J) = 175J useful energy.
(useful energy) / (energy supplied) = (175J) / (250J) = <em>70% efficiency</em>
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<u>Way #2: </u>
How much of the energy is wasted ? . . . 75J wasted
What percentage of the Input is that 75J ? . . . 75/250 = 30% wasted
30% of the input energy is wasted. That leaves the other <em>70%</em> to be useful energy.
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeee5454
