|How is it possible to calculate the velocity at the end of a ramp in a ramp problem when you are not given a mass magnitude?||Anonymous|
Tue. 06, Jul 2010, 00:02
|I would need to know more of the context, but you can use Kinematics if mass is not known. v = v_o + a*t; where a = g*sin(theta); t=time; v_o=initial velocity.||Douglas|
Tue. 06, Jul 2010, 05:54
How long did the collision occur? It would be helpful to know what the acceleration of the bus was in order to make a helpful translation of the events. Thanks!
Sat. 16, Oct 2010, 12:15
|Excellent question! That's why you are being paid the big bucks to be the expert witness! :)|
You are correct; to find the peak in impulse force we need to have an idea of the order of magnitude for the time of collision.
We don't know time of impact. But again, you are the expert here. In finding an estimate two things are important: possible range of values and how that range of values impacts your situation (no pun intended.)
Part of your analysis might be to show a range for common time values of a collision. You might start by looking at your data to see how long the collision took in lab. But the carts should travel in the same direction. Simulation would reveal an approximate value.
Airbag research might lead you to collision data found by car manufacturers. An airbag is designed to deploy on the order of tens of milliseconds (60-80 [ms] according this article: https://en.wikipedia.org/wiki/Airbag ).
You are probably safe to say for a "same direction" collision the time is between 1 and 0.1 [second]. The extreme case might be 0.01 [s]. But I'm not the authority on collisions; and you are the expert witness, so do not quote me for your assignment. :)
Sun. 17, Oct 2010, 04:14
I am a little confused on the part that says “moving at an uninhibited speed of about 35 [mph] when it hit the pole after sliding on ice.” Does this mean the bus was going at 35 mph after the collision?
Fri. 09, Mar 2012, 11:30
|"... the van was moving at an uninhibited speed of about 35 [mph]" (after the collision)||Douglas|
Fri. 09, Mar 2012, 11:59