d. the surface on which the object is moving is made smoother
This is called lubrication, I think ...
b. the weight of the moving object is decreased
If there is less araea of contact because of the weight reduction ("squeezing together") then this could also have an effexct. I thinl though the thrust of the q is on lubrication = oil, talcum powder, thin films of water etc
Please put answers in the comments of actual answers, as I need them! Lots of points! 63 points
Person standing on A will hear the loudest sound
Explanation:
The intensity of a sound wave (which is proportional to the loudness of the sound) follows an inverse square law, which is:

where
I is the intensity of the wave
r is the distance from the source of the sound
This equation means that the intensity of the sound wave (and therefore, its loudness) is inversely proportional to the square of the distance from the source: therefore,
- As we get closer to the source of sound, the loudness increases
- As we move away from the source of sound, the loudness decreases
Therefore, the person that will hear the loudest sound is the one standing closer to the source, and therefore person A.
Learn more about sound waves:
brainly.com/question/4899681
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See the attached picture:
They are blue because of hydrogen helium and methane