student@nmtvax.UUCP (07/09/83)
/**************************************************************** Two cars, one having twice the mass of the other, are driven into a brick wall. Neither driver is wearing a seatbelt. What is the difference, if any, between the speeds with which the drivers are thrown? Why? (Both cars are going the same speed initially; both drivers weigh the same amount.) ****************************************************************/ Initialy the two drivers are moving at the same velocity (assuming that they are going in the same direction ie. scalar vs. vector). When the cars impact the brick wall, assuming that the wall is thick enough to completely stop the foward momentum of the car, the heavier car has twice the momentum of the lighter but the drivers have the SAME momentum and velocity. If the cars are stopped instantously (well close enough not to matter) then the two drivers will go splat against the steering wheel with the same velocity, the same momentum, and the same kenitic energy. Better wear a seat belt. Not afraid to buckle up! Greg Hennessy; ..ucbvax!unmvax!nmtvax!student
kwmc@hou5d.UUCP (07/11/83)
Surely the effect on the drivers will be the same (allowing for random factors such as whether or not the steering wheel ruptures the spleen etc) if the wall remains INTACT. If the wall disintegrates, then the driver of the larger car will stand a better chance as the energy required to move the wall out of the way will result in less sudden decrease in speed than for the smaller car. Ken Cochran hou5d!kwmc
DWELD@BBNG.ARPA (07/12/83)
Aren't you assuming that the collision is completely inelastic? I would think that the car would bounce, at least some. And in that case the ratio of driver momentum to car momentum would be larger in the more massive car, thus the more massive car would bounce more, thus the driver of the more massive car would leave the seat with a higher relative velocity. Am I confused?