The doppler effect is the increase or decrease in the frequency of sound, light, or other waves as the source and observer move toward or away from each other.
That is called constructive interference. If they meet and cancel, it is destructive interference
Answer:
Explanation:
Analogy:
Who does more work:
Work done is defined as the product of force and distance. Work is done when force moves a body in a particular direction.
In this case, work done is the same thing as the potential energy of the weight.
Work done = potential energy = m x g x h
Mass of weight = 100kg for both Mike and Brian
g is the acceleration due to gravity
h is the height
Since they lifted the weight through the same height;
Work done by Mike = 100gh
Work done by Brian = 100gh
Both Mike and Brian does equal work
Who generates more power:
Power is the rate at which work is done;
Power = 
Power generated by Mike =
= 50gh
Power generated by Brian =
= 33.33gh
We can see that Mike generated more power