Answer:
The correct option is C
Explanation:
From the question we are told that
The initial speed of the rocket is 
The speed of the rocket engine sound is 
The final speed of the rocket is 
The speed of the sound at 
would still remain V this because the speed of sound wave is constant and is not dependent on the speed of the observer(The mountain ) or the speed of the source (The rocket ).
A clear example when lightning strikes you will first see (that is because it travels at the speed of light which is greater than the speed of sound) but it would take some time before you hear the sound of the
lightning
Here we see that the speed of the lightning(speed of sound) does not affect the speed of the sound it generates
The efficiency of a light source is the percentage of its energy input that gets radiated as visible light if some of the blue light in an led is used to cause a fluorescent material to glow the overall efficiency of the LED decreases.
How efficient is LED?
Different wavelengths that correlate to different visible colours are used in LED light therapy. Various shades pierce the skin at different rates.
- Your skin's outermost layer is impacted by blue light.
- Yellow light is more enveloping.
- Red light penetrates your skin more deeply.
- The deepest penetrating light is near-infrared.
Different LED hues have various effects. For instance, according to experts red LED light therapy has the potential to reduce inflammation and boost collagen formation, which declines with age and is crucial for maintaining youthful-looking skin.
Acne-causing bacteria may be destroyed by a blue LED light therapy (P. acnes).
Hence the answer is the overall efficiency of the LED decreases.
Learn more about wavelength here,
brainly.com/question/1263539
# SPJ4
The answer is A
Materials that are good conductors of thermal energy are called thermal conductors. Metals are very good thermal conductors. Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators
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as we know that the velocity vectors are at right angles
magnitude = ?
hypotenuse of a right
triangle.
v^2 = 90^2 + 4^2
v^2 = 8116
Taking the square root of both sides here we get,
v = 90.1 m/s
hope it helps
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