Answer to Question #117764 in Mechanics | Relativity for Yasmin

Question

you are in a card accident. your head had an initial speed of 14.4m/s when it hits an airbag which brings it to rest in 0.38s. if your head has a mass if 8.5kg, find the force on your head during the collision

Answer 1

According to the Newton's second law, the force during the collision will be:

$F = \dfrac{\Delta p}{\Delta t}$

where $\Delta p$ is changing in the head's momentum during the time $\Delta t$.

The initial momentum was $p_{start} = mv = 8.5\cdot 14.4 \space kg\cdot m/s= 122.4 \space kg\cdot m/s$, the final momentum $p_{end} = 0$. Thus:

$F = \dfrac{122.4}{0.37}N \approx 331 N$

Answer. F = 331 N.