Answer:
Only option A is correct
Explanation:
From the concept of Doppler effect, only speed matters. Thus, the faster a vehicle is moving, the closer together the sound waves get compressed and the higher the frequency. For example, for a very fast vehicle traveling at the speed of sound; the compressions are all right on top of each other. Thus, faster speed means closer compressions and higher frequencies. Hence, option only option A must be true because X is a higher frequency and so it must be going faster. The distance to the person will affect the volume but will not the pitch so Option B is not correct. Option C too is not correct because It doesn’t matter whether you are speeding up or slowing down, it only matters who is going faster. For example, from option c concept, if truck X was going 10 m/h and speeding up while truck Y was going 50 mph and slowing down, it would not meet the requirement that X has a higher frequency because only actual speed matters, not what is happening to that speed. Thus only option A is the correct answer
Answer:
Explanation:
Force 1 
Force 2 
Acceleration at stage 2 
Generally the weight of the Craft W is given as
W= upward force(thrust)
Therefore
Answer:
sound intensity is explained by the following formula I= P/A where I= sound intensity(W/m²),P=power(W),A= area(m²) I hope this helps good luck!
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Answer:
a-
50°C whn converted into K - 323 K
