How does the Doppler effect explain why a siren's pitch increases as it approaches you A. the siren's moves closer to sound waves it has already produced

B. the sirens moves away from sound waves it has already produced decreasing their wavelength

C. the siren moves away from sound waves it has already produced increasing their wavelength

D. the siren moves closer to sound waves it has already produced increasing their wavelength

The number of medals awarded to the track team during the season.

Answer : option a) 84explanation :

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.

Hope you find the answer

We first assume that this gas is an ideal gas where it follows the ideal gas equation. the said equation is expressed as: pv = nrt. from this equation, we can predict the changes in the pressure, volume and temperature. if the volume and the temperature of this gas is doubled, then the pressure still stays the same.