A30 g string is under 17 n of tension. a pulse travels the length of the string in 40 ms . how long is the string?
express your answer to two significant figures and include the appropriate units.

length of the string, l = 0.91 m = 91 cm

Given:

mass of string, M = 30 g =0.03 kg

Tension in string, T = 17 N

time taken for the pulse to travel, t = 40 ms = 0.04 s

Solution:

velocity of the pulse, v =             (1)

Also, v =                             (2)

From eqn (1) and (2):

Squaring both the sides of the above eqn, re-arrngingig and solving for length, l:

length, l = 0.91 = 91 cm

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.