Answer:
Explanation:
b ) The problem is based on Doppler's effect of sound
f = f₀ x (V - v₀) /( 
)
f is apparent frequency ,f₀ is real frequency , V is velocity of sound , v₀ is velocity of observer going away , 
is velocity of source going away
778 = 840 x (340 - 14)/ (340 + )
340 + = 341.18
= 1.18 m /s
it will go away from the observer or the cyclist.
speed of train = 1.18 m /s
a )
For a stationary observer v₀ = 0
f = f₀ x V /( )
= 840 x 340 / (340 + 1.180)
= 837 Hz
The application of force over distance is known as [WORK]
Answer: D. A wave with a shorter wavelength is always faster than one with a longer wavelength
Explanation: "Imagine two sets of waves that have the same speed. <u><em>If one set has a longer wavelength, it will have a lower frequency (more time between waves). If the other set has a shorter wavelength, it will have a higher frequency</em></u> (less time between waves). Light moves even faster AND has shorter wavelengths."
Why it's not C: "The number of complete wavelengths in a given unit of time is called frequency (f). <em><u>As a wavelength increases in size, its frequency and energy (E) decrease</u></em>. From these equations you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer."
Why it's not B: "The frequency does not change as the sound wave moves from one medium to another. Since the speed changes and the frequency does not, the wavelength must change."
Why it's not A: "Do loud sounds travel faster than soft sounds? No. Both travel at the same speed The speed depends on the medium it passes through. Louder sounds are simply sound waves with higher amplitude traveling at the same speed."
The first one is electrical energy
