Two speakers are connected to a signal source of 1000Hz and are set up 15 m apart. A person stands equidistant from each speaker so that each speaker individually produces the same intensity. When both speakers are on, the intensity is at a minimum. What could be the phase difference of the sound coming from the two speakers at this position?

0°

Explanation:

Since the speakers are equidistant from the person, there can only be constructive interference. . For constructive interference, the path difference ΔL = nλ a fractional number of wavelengths where λ = wavelength and n is a positive integer. For the intensity to be at a minimum, there must be destructive interference

λ = v/f where v = speed of sound in air = 343 m/s and f = frequency of signal = 1000 Hz

So, λ = v/f = 343 m/s ÷ 1000 Hz = 0.343 m

So for minimum intensity, n = 0

ΔL = nλ = (0)0.343 m = 0

So, the phase difference ΔФ = 2πΔL/λ  

= 2π(0 m)/0.343m

= 2π × 0

= 0°

sleep paralysis is a parasomnia, events associated with sleep.

sleep paralysis happens when you are in the middle of waking up or falling asleep. it is the feeling of being conscious but unable to move. it definitely involves hallucinations.

i had a friend that had sleep paralysis and he told me a story one time where he was laying in bed and he couldn't move his body no matter how hard he tried and there was someone standing in the corner of his room coming towards him. he couldn't move and you can't "wake up" because you are already conscious. sometimes sleep paralysis can be triggered by frequent waking up during the night based off of multiple trips to the bathroom, or if you had ever been abused, sleep paralysis can start happening from things like that.

think its the third option