on touching electroscope gets positively charged, so answer is B. conduction
Answer:
39.240 W
Explanation:
Let's start by calculating the work done by the engine. We can assume that it is the same work done by the weight of the object to bring it from 40m to the surface: as much energy it takes to bring it up, the same ammount it takes to bring it down. Said work is 
At this point we can simply apply the definition of power, that is
, to get the power of the engine is 
The Earth itself is a source of terrestrial radiation. Radioactive materials including uranium, thorium, and radium exist naturally in soil and rock. Essentially all air contains radon<span> , which is responsible for most of the dose that Americans receive each year from natural background sources.</span>
Answer:
A 5
Explanation:
The wave with the least amount of wavelength will have the greatest amount of energy.
Wavelength and energy shares an inverse relationship;
E = h f = 
From this equation, we see that the higher the energy of a wave, the lesser its wavelength.
- Choice A from the options has the least wavelength.
- Wavelength is the distance between two successive crests of a wave.
This is why we see that in the electromagnetic spectrum, radio waves have the least energy because they have the longest wavelength.