Question

You are the design engineer in charge of the crashworthiness of new automobile models. Cars are tested by smashing them into fixed, massive barriers at 56 km/h . A new model of mass 1800 kg takes 0.14 s from the time of impact until it is brought to rest.

Answer 1

Answer:

Those kind of question have the force and the acceleration as a questions

$a=111.11m/s^2$

$F=200kN$

Explanation:

Calculate the force exerted on the car by the barrier and the acceleration of the motion.

$v=56 \frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s}=15.56m/s$

$F=m*a$

Acceleration is the derive of the velocity so:

$a=\frac{dx}{dt}=\frac{15.56m/s}{0.14s}=111.11m/s^2$

Now replacing to find force

$F=1800kg*111.11m/s^2$

$F=200kN$