It's very tough to use the drop-down menus for this. I'll just do the best I can without them.
-- Objects with the same charge repel each other with electrostatic force, and attract each other with gravity. You can ignore the gravity because the electrostatic force is so much stronger.
-- Objects with opposite charge attract each other with electrostatic force, and also attract each other with gravity. You can ignore the gravity because the electrostatic force is so much stronger.
-- Objects with no charge have no electrostatic force between them, and they only attract each other with gravity.
There are no good descriptions on that list.
Answer: Option (C) is the correct answer.
Explanation:
When we heat a fluid then the movement within the fluid makes hot (less dense) material to rise and cooler (more denser) material to sink at the bottom. This process is known as convection.
Thus, in the diagram hot (less dense) water will rise and cooler (more dense) water sinks at the bottom.
Therefore, we can conclude that according to the arrow the label belongs to cooler water sinks.
B. Decreases
Why: Because the longer the wavelength the lower the frquency. The shorter the wavelength the higher the frequency.