I agree there are multiple moments when you feel weightless, your body is just floating above the seat.
This is the viper, the day at six flags it kept getting stuck but i still managed to get on before we left.

The top speed the viper hits is 50 mph. Which is 22.352 m/s

external image Six-Flags-Viper-601962.jpg
The Viper
The viper is a wooden rollercoaster located in six flags which opened in 1995, it's the only roller coaster direclty built by six flags.
It is the only wooden roller coaster to carry the name viper any other viper coaster has always been made out of steel.
It seats 30 passengers , and the carts are the same as American Eagle.
The Height is about 30 m and it can hold 1000 rides per hour.
The Viper has a drop that is about 24 m.
In 1998, the ride was not operating because it's manufacturer, TOGO, was troubled financially and went out of business,
In 2001, the coaster did not operate at all and was considered "standing but not operating".
Viper was not even listed on the 2001 park guides or the 2001 park map.

The Viper is one of my favorite rides because there are many moments when you feel weightless.