First we have to establish that the number of protons is equivalent to the atomic number of element. Here I am assuming that you are referring to Potassium (K) - 40. Potassium, stable or unstable has 19 protons.
Answer:
Doppler effect changes the wavelength of the light emitted, depending upon whether source is moving away or coming towards the observer(detector).
Explanation:
Doppler effect in light is actually a relativistic effect but somewhat similar to the one which happens in sound waves.
When the source is moving away from the detector, the wavelength of the light emitted from the source appears to be increased as seen by the detector, as a result the frequency decreases(we know that frequency of light= speed of light/wavelength of light. Here speed of light is constant and frequency of light is inversely proportional to its wavelength)
Due to this decrease in frequency the light emitted from the source appears more red, since red color is on low frequency side in the electromagnetic spectrum.
Similarly for the source moving towards the detector, the wavelength appears to be decreased, thereby resulting in increase in frequency and the source appears blue. The shift in frequency is known as doppler shift.
The shift in frequency when the source is moving away is known as redshift and the one where the source is moving towards detector is known as blueshift
Answer:
C. water is more dense and viscous
Explanation:
Rapid gas exchange can be accomplished more easily in air than in water because water is more dense and viscous.
Gases have the greatest ease of diffusion of their respective particles, as occurs in air, since their molecules have higher speeds and have more distance from each other than liquids.
The molecular diffusion rate in liquids is much less than in gases. The molecules of a liquid are very close (liquids are more dense and viscous) to each other compared to those of a gas, then the gas molecules hits with the molecules of the liquid with more frequency and this causes that the gas moves slower than in other gas (for example in air).
Answer:
The minimum acceleration will be
Explanation:
We have given that coefficient of static friction ![\mu _s=0.860](https://tex.z-dn.net/?f=%5Cmu%20_s%3D0.860)
Frictional force is given by ![F=\mu_s N=\mu _sma](https://tex.z-dn.net/?f=F%3D%5Cmu_s%20N%3D%5Cmu%20_sma)
Weight is given by ![W=mg](https://tex.z-dn.net/?f=W%3Dmg)
For train to allow the bat to remain in place ![mg=\mu _sma](https://tex.z-dn.net/?f=mg%3D%5Cmu%20_sma)
![a=\frac{g}{\mu _s}=\frac{9.81}{0.860}=11.40m/sec^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bg%7D%7B%5Cmu%20_s%7D%3D%5Cfrac%7B9.81%7D%7B0.860%7D%3D11.40m%2Fsec%5E2)
So the minimum acceleration will be ![11.40m/sec^2](https://tex.z-dn.net/?f=11.40m%2Fsec%5E2)