If the speakers are in phase, what is the smallest distance between the speakers for which the interference of the sound waves to the right of the speakers is maximum destructive

During takeoff, the sound intensity level of a jet engine is 170db at a distance of 34 m. what's the sound intensity level at a distance of 1.0 km?

What are similarities and differences of reflection, refraction, diffraction and absorption?

The seven sisters, seven stars located more than 400 light-years away in the taurus constellation can be seen here with venus and another constellation, orion. the seven stars stay grouped together but seem to move, like the planet venus. why do stars seem to move like planets in the night sky?