- #1
kjf123
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Not your average car collision (very "real life") - no values supplied
Hi,
I've been given an assignment on a theoretical car collision. However, it is very "real world" (we are given information regarding the condition of each car before and after [particularly the tyre tread -> coefficient of friction?], and the state of the drivers [reaction time?]).
Here's the general run down:
Car B (m = 887kg) skids for 11.38m and comes to a stop in the middle of an intersection.
Car A (m = 1,495 kg) essentially T-bones Car B. He does slam on his brakes and the skid mark from applying brakes to hitting Car B are 14.5m long.
The speed limit for the road is 13.88m/s (50kph). Here is where it gets tricky. We are not given any value for velocity. There are witness statements that think this guy has gone faster than the speed limit.
Car B (assumed no brakes applied) is pushed in a curved line... but I am going to only use the distance between the first point on the curve and the last = 2.935m (so a straight line). As a result of figuring out this straight line it occurs at an angle of 45deg.
Car A then continues onwards without its brakes applied and comes to rest after a distance of 17.419m.
Using http://hyperphysics.phy-astr.gsu.edu/hbase/images/astp3.gif I figured out the stopping distance of the car at any given speed.
From that I calculated acceleration (will this be constant regardless of speed?)
From calculating the acceleration (deceleration) I found out how long it took for him to travel the 14.5m, which in turn gave me a value for his velocity upon hitting the car.
Assuming what I have done is correct, I have no idea how to apply these numbers to the situation DURING and AFTER the collision?
I just don't know how to tackle this problem. This was assigned while learning our Momentum module.
So, the end goal is to work out as many mechanical/physical properties of both cars before, during, and after the collision.
Please note that I am not after an easy answer here. Just some guidance would be really helpful. Especially comment on my derivation of acceleration of his car.
I can upload the PDF file of the assignment if it makes the picture clearer. The diagram used, however, is not to scale and not a very good representation of the data.
Thanks for any help (just need a nudge in the right direction :) )
Karl
Homework Statement
Hi,
I've been given an assignment on a theoretical car collision. However, it is very "real world" (we are given information regarding the condition of each car before and after [particularly the tyre tread -> coefficient of friction?], and the state of the drivers [reaction time?]).
Here's the general run down:
Car B (m = 887kg) skids for 11.38m and comes to a stop in the middle of an intersection.
Car A (m = 1,495 kg) essentially T-bones Car B. He does slam on his brakes and the skid mark from applying brakes to hitting Car B are 14.5m long.
The speed limit for the road is 13.88m/s (50kph). Here is where it gets tricky. We are not given any value for velocity. There are witness statements that think this guy has gone faster than the speed limit.
Car B (assumed no brakes applied) is pushed in a curved line... but I am going to only use the distance between the first point on the curve and the last = 2.935m (so a straight line). As a result of figuring out this straight line it occurs at an angle of 45deg.
Car A then continues onwards without its brakes applied and comes to rest after a distance of 17.419m.
Homework Equations
Using http://hyperphysics.phy-astr.gsu.edu/hbase/images/astp3.gif I figured out the stopping distance of the car at any given speed.
From that I calculated acceleration (will this be constant regardless of speed?)
From calculating the acceleration (deceleration) I found out how long it took for him to travel the 14.5m, which in turn gave me a value for his velocity upon hitting the car.
Assuming what I have done is correct, I have no idea how to apply these numbers to the situation DURING and AFTER the collision?
The Attempt at a Solution
I just don't know how to tackle this problem. This was assigned while learning our Momentum module.
So, the end goal is to work out as many mechanical/physical properties of both cars before, during, and after the collision.
Please note that I am not after an easy answer here. Just some guidance would be really helpful. Especially comment on my derivation of acceleration of his car.
I can upload the PDF file of the assignment if it makes the picture clearer. The diagram used, however, is not to scale and not a very good representation of the data.
Thanks for any help (just need a nudge in the right direction :) )
Karl
