MovieChat Forums > MythBusters (2003) Discussion > Mythssion Control Error Spotted

Mythssion Control Error Spotted

posted 8 years ago by gbhsgbhs3
1 reply | jump to latest

First time seeing this one. Noticed almost immediately a problem with the way the swinging hammers were setup by Adam. He had hammers dropping from parallel to gravity to the bottom where gravity is balanced exactly below the pivot. However Adam then measured NOT the vertical drop for each to make them equal in drop measure, but instead measured the quarter circle (arc) length and put his 1x in the middle of the arc between the 90 degree mark on side to the bottom of the circle. Instead he should have drawn a parallel line at the bottom of the arc and one at the top of the arc, then measured for the halfway mark on a perpendicular line between them both and then drawn another parallel from that mark to the arc, which is where the true "half force" or 1x compared to his 2x would correctly have been.

So, what would this look line on the arc? The 1x mark would be higher on the arc than where Adam had it, giving more arc between the bottom and the 1x than between the 1x and the 2x. What determines the force is the drop, no matter if it's pivoted around an arc or direct drop with no pivot going straight down.

[–] stevebronco 7 years ago

Yes, it wasn't exactly half. But it was close enough to illustrate the result he wanted to achieve.

The real error was the misinterpretation of Jaimie's assertion (which was admittedly ambiguous). Jaimie didn't say the effect on the vehicle was the same as if it was going 100; he said the event (2 vehicles colliding head-on at 50) was the same as 1 hitting an immovable object at 100. And although the effect on each vehicle certainly isn't (as Adam proved), the events DO expend the same amount of energy and exhibit the same (net) force. The wall just couldn't be deformed, so all the deformation went into the single vehicle. If Adam's clay experiment had used a single slug at the point of impact each time, it would have shown what Jaimie said.

Motion is relative, and Jaimie's statement was correct from the frame of any ONE of the moving vehicles; but it was INcorrect from the frame of the wall or the observer (the ground).

Walk softly and carry a BIG SIX!!!