# Double check this problem/solution I made?

1. Mar 1, 2009

### mrbutter

I have to create my own physics question for homework which combines momentum/collisions with another unit (I chose forces/friction). Then I have to solve it.

1. The problem statement, all variables and given/known data

Lewis Hamilton is testing his new McLaren when suddenly he misses the pitlane break point and crashes into Kimi Raikkonen's Ferrari at 280 km/h. If Kimi was driving at 50km/h and the impact lasts for 0.3s and the coefficiant of friction is 0.3:
A) How far does each car slide?
B) Supposing that humans cannot survive over 80Gs, do either one of the drivers survive?

2. Relevant equations

impulse
p=p
F=ma

3. The attempt at a solution

280km/h = 77.7 m/s
50kkm/h = 13.9 m/s
m1v1 + m2v2 = m1v1 + m2v2
605(77.7) + 605(13.9) = 605(v1) + 605(v2)
V1 = 91.6 - V2

v1 - v2 = v2 - v1
77.7 - 13.9 = v2 - (91.6 - v2)
V2 = 77.7 m/s
v1 = 13.9 m/s

//KIMI RAIKKONEN SLIDE
vf^2 - vi^2 = 2(a)(s)
a = -Ff / m
a = -ug
a = 0.3(9.8) = -2.94
0^2 - (77.7)^2 = 2(-2.94)(s)
s = 1026.75m

//LEWIS HAMILTON SLIDE
vf^2 - vi^2 = 2(a)(s)
a = -Ff / m
a = -ug
a = 0.3(9.8) = -2.94
0^2 - (13.9)^2 = 2(-2.94)(s)
s = 32.85m

//G FORCE FOR LEWIS HAMILTON
v1 = 605(77.7) = 47008.5
v1 = 605(13.9) = 8409.5
change in momentum = v1 - v1 = 38599
38599 = F * t
38599 = F * 0.3
F = 128663
G force = F / 9.8 = 13128.9

//G FORCE FOR KIMI RAIKKONEN
v1 = 605(13.9) = 8409.5
v1 = 605(77.7) = 47008.5

change in momentum = v1 - v1` = -38599
-38599 = F * t
-38599 = F * 0.3
F = -128663
G force = F / 9.8 = -13128.9

Okay! Now the thing is, those G forces looks REALLY high. I mean obviously the crash is going to produce a big number but I was guessing it would be between 75-200. Right now as you can see it's in the thousands.

Did I miss something?

P.S. I realize that this is obviously missing like a million real-world factors but it's for a high school physics class so no need to make it excessive with stuff we have not learned yet.

Thanks!!