I had the same question wuth my 5 year old that begged me to take him.
My suggestion is to take the 5 year old through the line and stop when you see the train waiting to be launched. Let the child watch the launch, maybe two launches. Then ask if they want to do the ride. My son did not want to do it as soon as he saw the launch, despite being convinced and very excited to be doing the ride. No fear if they don't, their is a car for photos on the way out that you can take a photo keepsake.
By the way I had FP for the whole family and he was the only one to attempt it.
My suggestion is to take the 5 year old through the line and stop when you see the train waiting to be launched. Let the child watch the launch, maybe two launches. Then ask if they want to do the ride. My son did not want to do it as soon as he saw the launch, despite being convinced and very excited to be doing the ride. No fear if they don't, their is a car for photos on the way out that you can take a photo keepsake.
By the way I had FP for the whole family and he was the only one to attempt it.