Answer:
But there are ways to harness kinetic energy to either generate useful mechanical work or electricity. This is what many have tried to do to make use of energy that would be otherwise wasted. One way to harness kinetic energy that has popped up many times in recent years has to do with roads and speed bumps
Explanation:
A fire because you feed it wood, it lives longer but if you give it a drink, water, then it dies.
Pseudoscience
Pseudoscience is made of up statements, beliefs or practices that claim to be scientific and factual but are not based in the scientific method.
Complete Question
A commuter train passes a passenger platform at a constant speed of 39.6 m/s. The train horn is sounded at its characteristic frequency of 350 Hz.
(a)
What overall change in frequency is detected by a person on the platform as the train moves from approaching to receding
(b) What wavelength is detected by a person on the platform as the train approaches?
Answer:
a

b

Explanation:
From the question we are told that
The speed of the train is 
The frequency of the train horn is 
Generally the speed of sound has a constant values of 
Now according to dopplers equation when the train(source) approaches a person on the platform(observe) then the frequency on the sound observed by the observer can be mathematically represented as

substituting values


Now according to dopplers equation when the train(source) moves away from the person on the platform(observe) then the frequency on the sound observed by the observer can be mathematically represented as

substituting values


The overall change in frequency is detected by a person on the platform as the train moves from approaching to receding is mathematically evaluated as



Generally the wavelength detected by the person as the train approaches is mathematically represented as


