What is the crack-the-whip effect?
a.A sudden acceleration of the tractor
b.The tendency for the last trailer in a multi-trailer combination to amplify movements, making it sway more than the front trailers
c.A technique for backing up a double trailer
d.The sound brakes make when they are worn
Explanation
The crack-the-whip effect refers to how the last trailer in a combination amplifies any turning or swerving motion. A small movement at the front becomes a much larger movement at the rear, which can cause the last trailer to roll over.