As a motorcycle moves away from you, what happens to the amplitude and frequency of the sound it produces? -Both the amplitude and the frequency increases

-Both the amplitude and frequency decreases

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.