Galileo used inclined planes to investigate "freefall."
why did he do that instead of experimenting with velocitydropped
objects?

Because of the reason that the rate at which the velocity dropped object fall depends on their mass and may vary.

Explanation:

Galileo's investigation of free fall of objects using inclined planes led him to measure acceleration accurately and to conclude that all objects fall at the same rate irrespective of their masses under the action of gravity when the external forces on the object are absent.

Whereas as far as the velocity dropped objects are concerned they acquire different velocities for variation in masses.

Thus the velocity dropped objects may drop or fall at different rates and not at the same rate.

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.

c.the charges if the proton and electron and gravity