And, Dan, being able to apply conservation of momentum is critical in being a crash investigator. By examining the aftermath and applying c.o.m. you can determine the velocity vectors of the vehicles prior to the collision.

I believe it. But every time the crash investigator context appears, I’m left to wonder how students can interact with that context beyond a) recalling a formula, b) plugging in the right numbers, c) crunching the formula.

As I asked farther down this thread:

So is there a situation — even a simplified one — where one attorney might argue one thing and the attorney we work for as math consultants might use math to disprove her.

Any thoughts?

http://serc.carleton.edu/dmvideos/players/gauss_gun.html?hide_banner=true

There’s a lot here, but it at least starts a level of “huh?” that could work as a starting point for momentum to help fix.

Clearly an inelastic collision. Hence momentum is not conserved and the question is pointless. And, Dan, being able to apply conservation of momentum is critical in being a crash investigator. By examining the aftermath and applying c.o.m. you can determine the velocity vectors of the vehicles prior to the collision.

Putting the pieces together, I realized that this skill will be crucial when attacking the presentations of the opposing attorneys in injury lawsuits our students experience.

Cool, cool. Any interest in going farther down this road with me? It’s inconsistent, in my view, to wave my hands at a career that uses some math / physics, without also giving students a chance to feel that same power.

So is there a situation — even a simplified one — where one attorney might argue one thing and the attorney we work for as math consultants might use math to disprove her.

Dan, I could see this application being used in crash investigations because I do know they investigate velocity vectors of the cars, but that’s just a conjecture.

Super. This is a start. Now I need to know how knowing resultant momentum will help me become a more accurate, faster, or more certain crash investigator.

I like physics. And math. One without the other is school.

QOTD right there.

I mean, I don’t agree, but heckuva quote.

Surprisingly, the textbook at least gives reasonable values for the measures, at least at the bottom of our range from the plausibility investigation.

Now, why would you ever want to do this calculation? I think the answer lies in the result of the google search where I tried to find out how much people typically decelerate in a crash (expecting to bring my range for “velocity at the moment of the crash” down). Most of the hits were accident lawyers, fishing for clients.

Putting the pieces together, I realized that this skill will be crucial when attacking the presentations of the opposing attorneys in injury lawsuits our students experience.

Interesting comment on its place in a maths book. In the UK, we teach applications of mathematics as an integral part of the subject, especially in the 11th and 12th grades, when statistics, mechanics and discrete mathematics (algorithms etc) may all be part of the syllabus (the exact syllabus depending on the examination board and the choice of units). After all, much of mathematics has its origins in applications (especially in physics), so it seems a little bit strange to divorce our teaching of the subject from its wider meaning and application.