Since the sound travels from the submarine to the object AND back, it actually travelled 3625x2=7250m.
Speed of sound: 1450m/s
Answer:
73 db
Explanation:
A single air conditioner is equivalent to 70 dB frequency. An extra air conditioning unit would therefore double the sound frequency. It does not, however, double the decibels to 140 dB. Instead, it adds only 3 dB to the 70 dB, making the total decibels of two air conditioning units equal to 73 db
Hence the correct option is b that is 73 db
The answer is d that might help you