A toy cannon uses a spring to project a 5.30-g soft rubber ball. The spring is originally compressed by 5.00 cm and has a force constant of 8.00 N/m. When the cannon is fired, the spring decompresses and returns to its equilibrium length, causing the ball to speed up, before the ball enters the horizontal barrel of the cannon. The horizontal barrel is 15.0 cm long and it exerts a constant friction force of 0.032 N on the ball. A. With what speed does the projectile leave the barrel of the cannon

1.40 m/s

Explanation:

The potential energy of a compressed spring can be expressed as:

From above;

k = spring constant

x = distance of the spring (compressed)

From the barrel, the kinetic energy (i.e. the final K.E) of the ball is calculated using the relation:

where;

m = the ball mass

v = ball's speed

Equating both equations above, we have:

This can be re-written as:

replacing the values from the given information:

v ≅ 1.40 m/s

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.

reserve is the answer