Posted by **johny** on Wednesday, May 30, 2012 at 11:33am.

Imagine a car involved in a head-on crash. The driver, whose mass is m, is to be brought uniformly to rest within the passenger compartment by compressing an inflated air bag through a distance sc. Write an expression for the average force exerted on the bag in terms of m, vi, and sc. Compute the average force for a 100 km/h collision, where the driver’s mass is 60 kg and the allowed stopping distance in the bag is 30 cm.

i don't even understand this question....theres a lot going on in the question.....help needed..

- physics -
**Elena**, Wednesday, May 30, 2012 at 1:51pm
100km/hr = 27.78 m/s.

Through the Work-Kinetic Energy Theorem, the amount of work done by the air bag on the driver must equal the change in the driver's kinetic energy (the final kinetic energy is 0, the initial KE = m• v²/2)

ΔKE = W,

ΔKE = 0 - m• v²/2 = m• v²/2.

W =F(ave) •s(c).

m• v²/2 = F(ave) •s(c).

F(ave) = m• v²/2• s(c) =

= 60•(27.78)²/2•0.3 = 7.7•10^4 N.

## Answer this Question

## Related Questions

- physics - Imagine a car involved in a head-on crash. The driver, whose mass is m...
- Physics - A car traveling at 58 km/h hits a bridge abutment. A passenger in the ...
- Physics - A car traveling at 50 km/h hits a bridge abutment. A passenger in the ...
- physics - A car traveling at 69 km/h hits a bridge abutment. A passenger in the ...
- physics - A car traveling at 62 km/h hits a bridge abutment. A passenger in the ...
- Physics - In a simulated head-on crash test, a car impacts a wall at 25 mi/h (40...
- Physics - In a simulated head-on crash test, a car impacts a wall at 25 mi/h (40...
- physics - A car travelling at 60 km/h hits a bridge abutment. A passenger in the...
- physics - In a car crash, a 44 kilogram passenger moving at 15 meters per second...
- Physics - A 60kg front seat passenger in a car moving initially with a speed of ...