Need Help with Impact speed of a collision

[connorm935]

Hi can anyone help me figure this problem out
I had a crash which involved a police car and they have sent me a report from there on board system I can't work out the final impact speed of the collision that the police are was travelling
The crash happened after the 2 seconds of acceleration
I'm going to upload a photo that show the data

 

[blamocur]

I don't think it is possible to figure out the final speed. The last recorded speed is 25 mph, which about 11.17 m/s. Subsequent braking for 4 seconds at 3.3 m/s2 can potentially reduce the speed by 4s * 3.3 m/s2 = 13.2 m/s, i.e. can effectively stop the car. We cannot tell because we only know the max. deceleration, not the average.
Similarly, accelerating 3.3 m/s2 for 2 secs can potentially accelerate to 3.3 m/s2 * 2 s = 6.6 m/s ~ 14.77 mph, but we again don't know because we only know the max. value of the deceleration.

 

[connorm935]

I don't think it is possible to figure out the final speed. The last recorded speed is 25 mph, which about 11.17 m/s. Subsequent braking for 4 seconds at 3.3 m/s2 can potentially reduce the speed by 4s * 3.3 m/s2 = 13.2 m/s, i.e. can effectively stop the car. We cannot tell because we only know the max. deceleration, not the average.
Similarly, accelerating 3.3 m/s2 for 2 secs can potentially accelerate to 3.3 m/s2 * 2 s = 6.6 m/s ~ 14.77 mph, but we again don't know because we only know the max. value of the deceleration.

The crash happened approximately 120meters further down the road after the last logged acceleration event
The police officer driving said he slammed on just before impact and all wheel locked up and started to slide
At which point he assumed he was travelling under 30mph
3 people including the passager of the police vehicle witnessed the police car Travelling at approximately 40mph to 50mph travelling towards a set of traffic lights that was on red at which point the collision occurred approximately 16 feet after the traffic lights
At no point in the report does it record any further braking events from the last acceleration event

 

[connorm935]

A more detailed picture