Question

PLEASE ANSWER!!!!

A bus hits a car that is parked on the road from behind. The car accelerates in 7.5 m/ in 0.30 s. What force of the driver of the car experience assuming that the combined mass of the car and the driver is 2580 kg and that at the time if accident the driver is not using the seat belt? Compare this force assuming that the car has an airbag and the impact time is increased to 1 minute.

Answer 1

Acceleration of the car is given by

$a = \frac{v_f - v_i}{t}$

$a = \frac{7.5 - 0}{0.30}$

$a = 25 m/s^2$

Mass is given as m = 2580 kg

Now force is given by

$F = ma$

$F = 2580 * 25$

$F = 64500 N$

Now if air bags are open and the time is increased to t = 1 minute.

acceleration is given by

$a = \frac{7.5 - 0}{60}$

$a = 0.125 m/s^2$

Now force is given by

$F = ma$

$F = 2580 * 0.125$

$F = 322.5 N$

So the force is reduced when air bags are opened.