Answer:
ans 5
Explanation:
hope it's help It seems to me
Answer: D
Explanation: The chemical bonds in the food store energy that is released when we eat it.
Causes friction which slows movement down
Answer:
[negative sign denotes that it is moving away]
Explanation:
Actual wavelength of hydrogen spectral lines, 
Apparent wavelength of hydrogen spectral lines from a star,
<u>So, shift in wavelength</u>:



Using Doppler's shift:


[negative sign denotes that it is moving away]