me and my colleague watched Mercedes Benz commercial where its sports car accelerated, went in a tunnel, and made a complete loop around the tunnel by going up against the wall. Now, the debate was on whether a car can manage to make a loop in a same tunnel with same given velocity entering the loop, no acceleration once the car enters the loop, and manage to make a loop with heavier car (say, Ford F-150). With conservation of energy, it has same mass, gravity, and velocity, it must reach same height. But I think once the car hits 1/4 of the loop, centripetal force pulling down the car is greater so with same velocity Mercedes can make the loop, Ford F-150 may not. What do you guys think?