Driver experiences 17.68 G's on an average.
In the question,
We know that in a car crash the speed of the car goes from the speed of 26 m/s to 0 m/s in 0.15 seconds.
So,
The final speed, v = 0 m/s
Initial speed, u = 26 m/s
Also,
Time in seconds, t = 0.15 s
So,
Using the equation of law of the motion, we get,
v = u + at
0 = 26 + a(0.15)
a = -26/0.15
a = -173.33 m/s²
As, there is deceleration of the car is taking place the acceleration is in negative.
Now,
To convert it into the force in the G's we need to divide the deceleration by the acceleration (gravity), g.
So,
G's experienced by the driver on an average is given by,
[tex]\frac{173.33}{9.8}=17.68[/tex]
Therefore, on an average the driver experiences 17.68 G's.