Question

What is relative velocity? Suppose you want to design an airbag system that can protect the driver in a head on collision at a speed of 100 km/hr or 60 mph. Estimate how fast the airbag must inflate to effectively protect the driver? The car crumples within a distance of 1m.

Answer 1

0.072 seconds

Step-by-step explanation:

t = Time taken

u = Initial velocity = 100 km/h

v = Final velocity

s = Displacement = 1 m

a = Acceleration

`v^2-u^2=2as\\\Rightarrow a=(v^2-u^2)/(2s)\\\Rightarrow a=(0^2-((100)/(3.6))^2)/(2* 1)\\\Rightarrow a=-385.802469136\ m/s^2`

`v=u+at\\\Rightarrow t=(v-u)/(a)\\\Rightarrow t=(0-(100)/(3.6))/(-385.802469136)\\\Rightarrow t=0.072\ s`

The time taken is 0.072 seconds