~... PHYSICS CONCEPT ...~?

The metal has a much higher strength to weight ratio as well as greater tensile strength.

The corrugation ads strength as well as absorbs more energy by deforming on impact.

The energy The energy will be absorbed by the deformation of the metal as it crumplezand stretches. A same mass of wood will have splintered and failed long before the metal did

1) Obviously because metal is much stronger than wood. And secondly, if a car were to crash into them they would deform and absorb most of the energy, whereas wood would break and would not be as effective in stopping a car in the event of a crash.

2) Same reason why hose roofing iron is corrugated not flat, because corrugation improves rigidity. This corrugation effect can be demonstrated by holding a ruler flat on your palms, now grasp the ruler still with the flat side on you palms, then bend the ruler. It is very easy to do this but if you rotate the ruler 90 degrees so the thin side are against your palms not the flat sides, bending the ruler now become almost impossible without assistance. By corrugating roofing iron and safety barriers, this effect is achieved.

3)Well the kinetic energy of the car will be constant up until the point of impact. When this happens the car begins to slow down as it's kinetic energy is transferred to the barrier. Then this energy absorbed by the barrier translates to the deformation of the barrier. That's basically what happens :)

Hope these answers were detailed enough for you mate :) please remember to vote ;)

The UK's Highways Agency has issued documents (TD19 / 06) advising that all new safety barrier systems must be compliant with BS EN1317, this includes Standard Runs, Crash Cushions, End Terminals and Transitions.

1. safety barriers on highway made of metals because if accident occurs by mistake, you should fall in valley / water drainage / reducing min accidental chance.. Wood is not strong enough to hold running vehicle force to absorb

2. They are following BS Standard and have advantage over flat. By corrugated form, it is increasing the strength of the post, FLEXBEAM offers an increased performance with fewer component parts.

3. Nothing will happen except your front part will damage and you are safe and avoid major road accident.

1) metal has a higher tensile strength, at the high speeds a car travels on highways, wooden fences will break easily with little impact on the car's kinetic energy.

2) the corrugated surfaces provide friction. this friction helps to keep a grip on the car bumpers and stop it. else the bumper will slide off and the car may skid away and hit something else.

3) the kietic energy gets converted back into petential energy, heat and sound energy on hitting the fence. some of it will of course get transmitted to the barrier.