Answer:
is Bob's average acceleration.
Explanation:
Initial velocity of the bob's in-lineskates= u = 0 m/s
Acceleration of the Bob= a = ?
Final velocity of the bob's in-lineskates= v = 4.5 m/s
Duration of time in which 0 m/s velocity is changed to 4.5 m/s = t = 15 s
Using first equation of motion: v = u + at
is Bob's average acceleration.
Aortic valve prevents backflow of blood into the left ventricle and creates the second, dubb sound.
The mitral, tricuspid, pulmonary, and aortic valves are the four heart valves that keep blood flowing in the right direction. Flaps (leaflets) on each valve open and close once per heartbeat.
The mitral and tricuspid valves transport blood from the upper chambers of the heart (the atria) to the lower chambers of the heart (the ventricles). The aortic and pulmonary valves transport blood to the lungs and the rest of the body via the ventricles.
Blood flowing through the heart chambers creates heart sounds as the cardiac valves open and close during the cardiac cycle. The vibrations of these structures caused by blood flow produce audible sounds.
To learn more about valves of the heart, here
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Answer:
I believe it may be "B" so hopefully it's right
The permanent gases whose percentages do not change from day to day are nitrogen<span>, </span>oxygen<span> and</span>argon<span>. </span>Nitrogen<span> accounts for 78% of the atmosphere,</span>oxygen<span> 21% and </span>argon<span> 0.9%. Gases like </span>carbon dioxide<span>, nitrous oxides, </span><span>methane</span>
