Answer: The sound will change due to changes in frequency and the wavelength of the airplane.
Explanation: Let assume that the observer is at a stationary position. The wavelength of the sound from the airplane reduces and the frequency increases as the plane is moving toward the observer. As the airplane passes by, that is, moving away from the observer, the frequency starts to reduce while the wavelength of the sound starts to increase.
The sound that the observer hears will change base on the illustration above.
acceleration = Velocity changes ÷ time of the velocity changes
4 m/s^2 =
4 × 10^(-3) × 3600 km / h =
4 × 3.6 =
14.4 km / h
Thus :
14.4 = V(2) - V(1) / t(2) - t(1)
14.4 = V(2) - 20 / 10
Multiply both sides by 10
10 × 14.4 = 10 × ( V(2) - 20 ) / 10
144 = V(2) - 20
Add both sides 20
144 + 20 = V(2) - 20 + 20
V(2) = 164 Km/h
Thus the final velocity after 10 seconds is 164 Km/h .
<span>The true brightness of an object
is called its luminosity. It is the total amount of energy emitted by bright or
meteorological objects over a period of time. It has the SI unit of joules per
second or watts. So the answer is letter A. Intensity is the measure of how
strong the substance or object is when it projects something. Magnitude is a
measure of how great is the size the object produces. Viscosity is the measure
of flow of a substance.</span>
Wind or gravitational pull. A wave is made by friction between wind and the water’s surface. Waves can also be made by the sun and moon’s gravitational pull on the earth.
