View Question
 Question
 Subject: falling from moving vehicle Category: Science > Physics Asked by: dubbler415-ga List Price: \$2.00 Posted: 11 Aug 2006 08:18 PDT Expires: 10 Sep 2006 08:18 PDT Question ID: 755025
 if you fall from the back of a moving vehicle at highway speeds do you roll the same way as the vehicle is moving or the opposite on inpact
 There is no answer at this time.

 Subject: Re: falling from moving vehicle From: markvmd-ga on 11 Aug 2006 08:55 PDT
 Same way, 'cuz that the direction you are already going, and pretty fast. I hopped off the back of a moving station wagon tailgate once and learned an important physics/relativity lesson.
 Subject: Re: falling from moving vehicle From: qed100-ga on 11 Aug 2006 09:27 PDT
 If you literally just fall off the back of a moving car, in other words you just slip off, making no effort to shove off and negate any of the car's speed, then you'll land on the pavement moving at the same speed as the car. Thus, the side of you which comes first into contact with the road will be subject to frictional drag. The part of your body scraping against the asphalt will lose speed even as the opposite side persists onward due to its inertia. So your top & bottom will be traveling at different velocities, the top moving forward faster than the bottom. You'll quickly end up rolling in the same direction as any of the wheels of the car off which you just fell. (You'll also get pow'rfully hurt!) But let's say that you are uncommonly strong. You might then shove off the rear of the car, accelerating away from it. If you shove off hard enough you'd subtract from your speed that of the car, and land with zero speed relative to the road surface. If you were even a lot stronger, you could subtract more than the car's speed relative to the road, giving you the velocity of a car traveling in the opposite direction. In that case, you'd roll in the other direction. Don't try any of this. :)
 Subject: Re: falling from moving vehicle From: markvmd-ga on 11 Aug 2006 20:42 PDT
 Qed100, shoving off at about 30m/s? Human muscles aren't capable of such acceleration, the bones they attach to aren't strong enough for such stresses, and the joints cannot resist that much motion. I expect there's a state law against it as well. If not, this is something that should be taken up with the local legislature. Beats selecting a state legume... I was the one watching Lee Majors with my 10 year old peers and saying, "But it really can't be done" and getting pillows thrown at me.
 Subject: Re: falling from moving vehicle From: qed100-ga on 12 Aug 2006 05:24 PDT
 "Qed100, shoving off at about 30m/s?" Indeed. That's why I proposed, "But let's say that you are uncommonly strong." At highway speeds, one would be very uncommonly strong, even to the point of being unhuman! :)
 Subject: Re: falling from moving vehicle From: redkev-ga on 31 Aug 2006 03:48 PDT
 In my youth around Dublin, Ireland they had double decker buses with an open platform at the back with a vertical pole in the middle of the platform at the edge. It was common practice to lean out holding the pole and drop off the bus while it was still moving as it slowed for a stop. In order to survive this unscathed you had to judge exactly the right moment to drop. To early and you rolled base over apex in the direction of the bus to late and you were subject to the derision of your mates. Get it right and you had to run really fast in the direction of the bus avoiding people and street furniture. The slap of your second foot to hit the ground actually hurt!