justicejesusfreak

19.04.2021 • 

Physics

Fishing sonar. The attenuation constant for sound waves in water increases with frequency. Consider the sonar used for fishing. The reflection of sound from fish schools is used for sports and commercial fishing. Fish produce relatively large reflections because of their air sack, the reflection being due to the interface between flesh and air, whereas the reflection at the interface between flesh and water is small. The signal is generated by an ultrasound actuator and detected by an ultrasound sensor. Suppose the actuator produces a power of 0.1 W at 50 kHz (a common frequency in fishing sonars) and the power propagates in a relatively narrow beam. Assuming that 20% of the sound reaching a fish school is reflected and that reflected sound is scattered uniformly over a half-sphere, calculate the required sensitivity of the ultrasonic sensor (in W/m2 ) to detect a fish school at a depth of 20 m. Attenuation in water at 50 kHz is 15 dB/km.

Ответ:

miklin4677

24.08.2020

Physics

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The orbital diagram represents the filling of electrons in the sub levels of an orbit. The filling of the orbitals in sub- levels follow some basic rules and principles.

The orbital diagram of an orbit containing 16 electrons will be as follows:

    1s²2s²2p⁶3s²3p⁴

The maximum number of electrons in each sublevel of the orbitals are:                  2 electrons for s-sublevel with one orbital                  6 electrons for p-sublevel with three orbital                  10 electrons for d-sublevel with five orbital                  14 electrons for f-sublevel with seven orbital

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