I'm flying, Jack!
This is a video of a real human slingshot that launches BASE jumpers 300-feet into the air, blasting off from 0 - 200km/h (~124MPH) in one second. A human projectile experiences 6G's of force during launch before having the opportunity to deploy their parachute and drift safely back to earth. Me? There is absolutely no doubt in my mind I would pass out during launch and splatter below like a dead goat catapulted over a castle wall.
Keep going for a video demonstration, including first-person perspective.
Thanks to DieselNuts, who may or may not be a moving truck and not made for flying.