Oscillation of a 260 hz tuning fork sets up standing waves in a string clamped at both ends. the wave speed for the string is 640 m/s. the standing wave has four loops and an amplitude of 3.1 mm.
(a) what is the length of the string?
(b) write an equation for the displacement of the string as a function of position and time. round numeric coefficients to three significant digits.

Answer

given,

frequency of the tuning fork = 260 Hz

speed of wave in the string = 640 m/s

number of loop = n = 4

Amplitude = 3.1 mm

a) wavelength of the spring

we know length of string

b) angular frequency of standing waves

  ω = 2 π f  = 2 π x 260

  ω = 520 π rad/s

  wave number

       k = 2.723 rad/m

 y (x,t) = Ym sin(kx)cos(ωt)

 y (x,t) = 3.1 sin (2.723 x) cos(520 π t)

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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.