Salt concentration is the factor among the following factors given in the question that does not vary between a fast flowing river and a pond that receives no water input. The correct option among all the options that are given in the question is the second option. I hope the answer comes to your help.
It's an sight observation you're using your eyes to see it it's one of your 5th sences
Skate park is a good example that maintains the law of conservation as skater neither creates nor destroys energy.
Explanation:
As per the law of energy conservation, energy cannot be created nor can be destroyed but it’s form can definitely be changed. This theory can be well justified by the example of skate park playground. According to the rules of this law a skater can never go high more than 2 meters on the ramp’s other side because it has that gravitational energy potential.
With every drop of the skater on the ramp the potential energy of the skater changes into kinetic energy. This two sides of the law justifies the fact that skate playground should be designed in such a way that it supports the law of conservation of energy.