A car moving at 108 km $h^{- 1}$ finds another car in front of it going in the same direction at 72 km $h^{- 1}$ . The first car sounds a horn that has a dominant frequency of 800 Hz. What will be the apparent frequency heard by the driver in the front car? Speed of sound in air = $330 m s^{- 1}$

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Solution

According to the question, velocity of car $A = V_{A} = 108 k m / h = 30 m / s$

$V_{B} = 72$ km/h =20 m/s, f=800 Hz

So, the apparent freqency heard by the car B is given by,

$f^{1} = (\frac{330 - 20}{330 - 30}) \times 800 = 826.9$

\simeq 827 Hz

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A car moving at 108 km h−1 finds another car in front of it going in the same direction at 72 km h−1. The first car sounds a horn that has a dominant frequency of 800 Hz. What will be the apparent frequency heard by the driver in the front car? Speed of sound in air =330ms−1

According to the question, velocity of car A=VA=108km/h=30m/s VB=72 km/h =20 m/s, f=800 Hz So, the apparent freqency heard by the car B is given by, f1=(330−20330−30)×800=826.9 \simeq 827 Hz

A car moving at 108 km $h^{- 1}$ finds another car in front of it going in the same direction at 72 km $h^{- 1}$ . The first car sounds a horn that has a dominant frequency of 800 Hz. What will be the apparent frequency heard by the driver in the front car? Speed of sound in air = $330 m s^{- 1}$

According to the question, velocity of car $A = V_{A} = 108 k m / h = 30 m / s$

$V_{B} = 72$ km/h =20 m/s, f=800 Hz

So, the apparent freqency heard by the car B is given by,

$f^{1} = (\frac{330 - 20}{330 - 30}) \times 800 = 826.9$

\simeq 827 Hz