A Big Rig Crossing a Bridge

An 18-wheeler is crossing a 4 kilometer bridge that can only support 10,000 kilograms and that’s exactly how much the rig weighs. Halfway across the bridge a 30 gram sparrow lands on the cab, but the bridge doesn’t collapse. Why not?

Since the bridge is 4 kilometers long, the halfway point would be 2 kilometers. The 18-wheeler would have used much more than 30g of fuel to drive 2 kilometers.

Posted in Brain Teasers


2 Comments on "A Big Rig Crossing a Bridge"

Mehul kumar says
November 28, 2015 @ 11:08

As bridge is 4 km long rig consumed more than 30 gm of fuel

Dan says
May 13, 2016 @ 05:34

Could the wheeler be more than 2km long? Therefore full weight is not on the bridge when the sparrow arrives?

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