3. Coal burning
The coal releases chemicals when it is burned. So it is chemical to thermal.
Explanation:
Below is an attachment containing the solution.
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:
Explanation:
Speed of the source of sound = v = 44.7 m/s
Speed of sound = V = 343 m/s
a) Apparent frequency as the train approaches = f = [V /(V -v) ] × f
= [343 / (343 - 44.7) ] × 415 = 477.18 Hz
Wave length = λ = v / f = 343 / 477.18 = 0.719 m
b) Frequency heard as the train leaves = f ' = [V / ( V + v) ] f
= [343 / { 343 + 44.7 ) ] x 415
= 367.2 Hz
Wavelength when leaving = v / f = 343 / 367.2 = 0.934 m
