Light Emitting Diodes (LEDs) are semiconductor devices that emit light at specific wavelengths without emitting at any other wavelengths. LEDs can be used to create lasers that are very compact since they are a solid state device. A pair of narrow, parallel slits separated by 0.267 mm are illuminated by the green LED laser (λ = 546.1 nm). The interference pattern is observed on a screen 1.35 m from the plane of the parallel slits.

What is the distance between the first and second dark fringes?

Δx = 2.76 x 10⁻³ m = 2.76 mm

Explanation:

The distance between any two consecutive dark or consecutive bright fringes is given by:

Δx = λL/d

where,

Δx = distance between first and second dark fringe = ?

λ = wavelength of light = 546.1 nm = 546.1 x 10⁻⁹ m

L = distance between slits = 1.35 m

d = slit separation = 0.267 mm = 2.67 x 10⁻⁴ m

Therefore,

Δx = (546.1 x 10⁻⁹ m)(1.35 m)/(2.67 x 10⁻⁴ m)

Δx = 2.76 x 10⁻³ m = 2.76 mm

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.

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explanation: