MCQ
A stationary source is emitting sound at a fixed frequency $\mathrm{f}_0$, which is reflected by two cars approaching the source. The difference between the frequencies of sound reflected from the cars is $1.2 \%$ of $f_0$. What is the difference in the speeds of the cars (in $\mathrm{km}$ per hour) to the nearest integer? The cars are moving at constant speeds much smaller than the speed of sound which is $330 \mathrm{~ms}^{-1}$.
- ✓$7$
- B$9$
- C$3$
- D$5$
