Science Smackdown: Nissan Frontier Snowboarding AdS

This one's a bit less heinous than the airplane-using-the-truck-as-landing-gear one, but it's still pretty stupid. You would think there would be plenty of genuine, existing things you could show a 4-wheel drive truck doing to support snowboarders, but I suppose that was all too boring for the brain of that 7-year-old that the ad agency keeps in a jar to come up with this crap. Here's our physicist, Dr.Stephen Granade, to tell us why this just won't happen, with science:


All right, let's talk about the snowboarding truck. Slaloming is at least theoretically possible, though I don't know how well the truck could make those turns given the snow. Where things really go off the rails is the barrel roll.

If you watch snowboarders do a barrel roll, they kick off and then tuck their knees to their chest. The kick sets them spinning about their center of mass and then by tucking their knees in they spin faster. It's like how ice skaters can spin faster by pulling in their arms or slower by putting their arms out.

Let's talk momentum for a minute. When you start spinning, you build up angular momentum, just like when you run forward you build up (linear) momentum. Momentum in general is mass times velocity; for angular momentum it's moment of inertia times the velocity at which you're spinning (angular velocity). If you don't apply any outside forces (like friction or gravity), then your momentum won't change.

Your moment of inertia, roughly speaking, is how your mass is distributed with respect to your center of mass. When skaters stick their arms out, their moment of inertia increases and so their angular velocity has to go down to keep angular momentum the same — they spin more slowly. When they pull their arms in their moment of inertia decreases and their rate of spin goes up.

Back to snowboarders. The kick starts them rotating; the knee tuck decreases their moment of inertia so they can rotate fast enough to land on their feet given the limited amount of air they can get. But the truck can't kick off to start itself rotating! The only way it would start rotating is if the hill it was coming up was banked as it went higher so that the truck was already rotating before it left the ground. And you'd need a heck of a bank to get any appreciable rotation. Making it worse, the truck can't change its moment of inertia to make itself rotate any faster.

Then there's the question of what happens when it lands. It flies up in the air, then lands much lower down the hill. I'm estimating based on the video that, from its highest point, the truck falls nearly ten times its own height. So it's like dropping the truck from 55 or 60 feet up. I'd hate to see what that does to the truck's suspension, even with the snow.

Because of that, I vote for Not Very Plausible. The truck would come over that hill and maybe rotate a little bit before it crashed into the ground at a high rate of speed.

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