The vibrations of a string fixed at both ends are represented by y=16sin(πx/15 )cos(96πt). Where x and y are in cm and t in seconds. Then the phase difference between the points at x=13cm and x=16 in radian

Explanation:

y = 16 sinπx/15 cos(96πt)

When t = 0

y = 16 sinπx/15

here πx/15 is phase of the point at x

if x = 13

Phase = 13π/15

if x = 16

Phase = 16π/15

Phase difference

= 16π/15 - 13π/15

= 3π/15

= π/5 radian .

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.

amplitude

hope this