WOULD IT BE A NICE IDEA TO FIT OUR CARS WITH THICK RUBBER LIKE THOSE IN BUMPER CARS?
When metal gets crumpled it absorbs the energy permanently. A rubber bumper would be elastic and try to make the cars “bounce apart” again. That’s good fun on a fairground ride, but it would not be a good idea to have a cars “bouncing” around after a high speed road accident. While the metal is being crushed the force it transmits to the rest of the car is almost constant, unlike a rubber bumper which would transmit more force as it was compressed more (like a spring), and therefore cause higher accelerations and more potential damage to the passengers. In a head-on collision modern cars can be crushed a very long way (maybe 0.5m) without causing any damage to the passenger compartment. Adding at least 0.5m thickness of rubber to the front of the car would not be very practical even if it absorbed the energy permanently. Some vehicles already have crushable foam plastics (similar to foam rubber) filling the empty spaces inside the metal components, because it is light weight and absorb
Thick rubber works well on bumper cars because they do not reach high velocity. A band of rubber protects the entire car because all cars are identical. Automobiles have much greater mass and reach much higher velocities where the thick rubber could not absorb all the energy of impact. The amount of rubber needed for a typical car for even low velocity parking lot fender benders would add to the weight of the vehicle and reduce gas mileage (increasing greenhouse gases). Using rubber/plastic/metal bumpers that flex on impact rather than crumple might reduce repair bills for moderate head-on impacts.
bumper cars go relatively slow and are relatively light compared to cars, the reason the bumper crumples is to decelerate the car to 0 in the longest time possible, imagine if both cars were solid steel, you would just splat inside the car on collision with another, crumpling is vital, the rubber you reference is far too resistant to compression compared to metal crumpling, hope this clears it up for you.
