Atoy rocket is launched from a 2.8 m high platform in such a way that its height, h (in meters), after t seconds is given by the equation h equals negative 4.9 t squared plus 18.9 t plus 2.8. how long will it take for the rocket to hit the ground?

3.98 s (approximately 4 s for practical purposes)

Explanation:

1) Equation given:

h(t) = - 4.9 t² + 18.9 t + 2.8

2) The time it will take the rocket fo hit the ground is given doing h (t) = 0

- 4.9 t² + 18.9 t + 2.8 = 0

3) You can solve that equation using the quadratic equation or working the equation to complete squares.

To use the quadratic equation you have a = - 4.9, b = 18.8, and c = 2.8

With that, t = [-18.8 +/- √ ( 18.8² - 4(-4.9)(2.8) ) ] / (2(-4.9) ) = 3.98 s

(I only picked the positive result because the negative does not have physical meaning).

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.