Roller Coaster General Question

[n3w ton]

I got a question:

If a roller coaster is going up the hill (potential energy) then when it goes down it gets converted into kinetic energy by gravity right?

Also As you go down the first big drop of the roller coaster (gravity going downwards 9.81 m/s²) how does acceleration come in play?

I know when you go down a roller coaster at a certain point : gravity and acceleration balances each-other out giving the effect of 'weightlessness' but where does the acceleration come from?

Also can acceleration [Upwards] exceed the value of gravity[downwards] on a roller coaster?

My attempt: I think the acceleration comes from the downward effects of gravity as the roller coaster cart travels down the first big drop,,,, then gravity at -9.81m/s²[Down] and the acceleration of +9.81m/s²[Up] balance at a certain point giving the effect of weightlessness.


THANK YOU VERY MUCH!

 

[JaredJames]

Woah there, gravity = acceleration.

You feel weightless because you are in free fall during the decent, there is no normal force. Nothing to do with "acceleration balancing" - you can't accelerate upwards and downwards at the same time.

Acceleration upwards, sideways and downwards can certainly be greater than gravity, particularly during sharp turns and loops.

 

[rcgldr]

To get into "free fall" the roller coaster picks up some amount of horizontal velocity, then follows a parabolic like path that keeps it in free fall for a brief period. At the bottom, passengers will typically experience 1.5g or more of acceleration plus the 1g from gravity for a total of 2.5 g's or more. Some roller coaster get up to about 5 g's total acceleration at the bottom of dips or curves.