Your math is wrong. Kinetic energy scales linearly with mass, quadratically with speed. The graphic you included supports the idea that at same speed, the pickup truck has double the KE. The 120 mph sedan has dramatically more KE than a 30 mph pickup.
Assuming that your sedan has exactly half the mass of the pickup, it would match a 30 mph pickup’s KE at 30*sqrt(2) mph, which is somewhere between 40 and 45 mph.
Your math is wrong. Kinetic energy scales linearly with mass, quadratically with speed. The graphic you included supports the idea that at same speed, the pickup truck has double the KE. The 120 mph sedan has dramatically more KE than a 30 mph pickup.
Assuming that your sedan has exactly half the mass of the pickup, it would match a 30 mph pickup’s KE at 30*sqrt(2) mph, which is somewhere between 40 and 45 mph.