I think it’s the first one
When sounds at two different frequencies are combined,
two new sounds are created ... at the sum and difference
of the original frequencies.
Combining two sounds at 490 Hz and 488 Hz creates
beats at 978 Hz and 2 Hz.
The fluttering "wah wah" effect of the 2 Hz beat is much more
noticeable than the new sound at 978 Hz.
Longitudinal waves transfer energy parallel to the direction of the wave motion
The rock strike the water with the speed of 15.78 m/sec.
The speed by which rock hit the water is calculated by the formula
v=
v=
v=15.78 m/sec
Hence, the rock strike the water with the speed of 15.78 m/sec.
Answer:
thanks for da 5points hoi
Explanation: thanks dawg