-I believe the star gives off energy-, With<span> most </span>stars<span>, like our sun, hydrogen </span>is<span> being converted into Helium, a process which gives </span>off<span> energy that heats the </span>star<span>.</span>
D) The speed of a wave slows as it travels at different speed in different media.
Answer: 0.392 m/s
Explanation:
The Doppler shift equation is:
Where:
is the actual frequency of the sound wave
is the "observed" frequency
is the speed of sound
is the velocity of the observer, which is stationary
is the velocity of the source, which are the red blood cells
Isolating :
Finally:
repeated mesurement can reduce the error
it is true
if you take any mesurement repeatedly and the average is taken, the error will be less