Answer:
a. wavelength of the sound, 
b. observed frequecy, 
Given:
speed of sound source,
= 80 m/s
speed of sound in air or vacuum,
= 343 m/s
speed of sound observed,
= 0 m/s
Solution:
From the relation:
v =
(1)
where
v = velocity of sound
= observed frequency of sound
= wavelength
(a) The wavelength of the sound between source and the listener is given by:
(2)
(b) The observed frequency is given by:


(3)
Using eqn (2) and (3):


Number 13 is D the heart has 4 chambers and pumps blood to the arteries and number 14 us C
When oxygen is present, cellular respiration produces carbon dioxide, water, and energy in the form of ATP.
When oxygen is not present, cellular respiration produces lactic acid or alcohol.
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Explanation:
answer is the 3rd law of motion
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