Explanation:
The lines in the spectra of star is due to absorption of light emitted by star by different elements present in atmosphere of the star .
If some element is present in the outer atmosphere of he star , it will absorb a particular portion of light , for which there will be black line in the spectrum .
These are called Fraunhoffer's lines .
Now there is no such line at the place of Helium in the light spectrum . This means that Helium element is not present in the outer atmosphere of the star.
<span>1.
</span><span>Efficiency is the
measure of how efficient a process is. It is used to assess the ability of a
process in avoiding waste energy, materials, money and time in doing a
desirable output. It is calculated as;
Efficiency = useful energy ouput / total energy input</span>
<span>.40 = useful work / 200</span>
<span>useful work = 80 joules</span>
Answer:
b: false
Explanation:
It's true that endothermic reactions absorb heat from their surrounding. But this makes the surroundings cooler, not warmer.
Answer:
The input force that you use on an inclined plane is the force with which you push or pull an object. The output force is the force that you would need to lift the object without the inclined plane. This force is equal to the weight of the object.
Explanation:
Microwave because they are powerful and available can be d answer
