Boy!
I would FLY out of the car going forward because the car stopped going in a forward motion. Same in reverse. No gravity involved there per say
We'd have to present a similar situation dealing with centrifugal force
A better example is a merry go round
While at rest I can comfortably sit on the merry go round without fear of being tossed off
But while spinning, the inertia of my body wants to THROW me away from the center of the spinning object. And the larger I am, the more force is pushing me away from the center.
So thats what I meant about Gravity and why they needed it and why it has to be in a massive scale
We can't even stand still on a playground equipment spinning fast
So imaging how powerful something as massive as the ball Earth spinning THAT fast would be
And with a gravitational force that has to counteract that, holding water down, holding air in place. Holding the heavy molten core below ....
It doesn't even add up how we can jump tbh or how birds and balloons fly. Using common sense and not a mythical equation they never finished