We assume that horn releases sound of constant frequency. In order for observer to observe different frequency either horn or observer or both must move.
This happens due to Doppler effect. It states that when position of source of sound and observer relative to each other changes, the observed frequency also changes. If the source emits sound of constant frequency than observed frequency will be either higher or lower than original.
When distance between source and observer increases the observed frequency will be lower. This is because same number of sound waves must cover greater distance so they have greater wavelength.
When distance between source and observer decreases the observed frequency will be higher. This is because same number of sound waves must cover smaller distance so they have smaller wavelength.
Wavelength and frequency are inversely proportional meaning when one increases the other drecreases.
From this explanation we can find answer for our question. <span>If we wanted the pitch of a horn to drop relative to an observer we need to move horn away from an observer.</span>
Answer:
t = 4.1 seconds
Explanation:
It is given that,
Width of road which is to be crossed by a man is 8.25 m, it means it is distance to be covered.
Speed of man is 2.01 m/s
We need to find the time taken by the man to cross the road. It is a concept of speed. Speed of a person is given by total distance covered divided by time taken. So,
t is time taken
So, the time taken by the man to cross the road is 4.1 seconds.
Answer:
D.Entropy tends to increase.
Explanation:
The second of thermodynamics states that the state of entropy of the entire universe,as an isolate system, will always increase over time
Answer:
1)Fuel Sourcing
2)Power Generation
Explanation:
1)Fuel Sourcing
: Fossil fuels must be located, excavated and transported before they can be used. These processes are invasive and detrimental to the land through side effects such as erosion as well as ecological and geologic instability. Then the deposit or well is depleted. Energy from the sun is infinite and free. It can be harnessed and turned into power anywhere a solar panel can be mounted.
2)Power Generation:
Fossil fuels must be burned to produce electricity. Burning them creates unwanted byproducts that can create air and water pollution and release huge amounts of greenhouse gasses into the atmosphere.
