00:01
Two cars, both with the mass of 1 ,700 kilograms and traveling at a speed of 24 meters per second, are crashed as a part of safety investigation, and they are brought to a stop.
00:18
One, i'm going to call this t1, stops in a time of 1 .5 seconds, and the other one stops in a time of 0 .2 seconds.
00:27
And so we want to find the force exerted on both of these different vehicles.
00:34
And we want to express them into two significant figures when we do so.
00:39
And so to do this, we're going to use the impulse momentum theorem, where impulse is equal to change in momentum, where change in momentum is momentum final minus momentum initial, and impulse is simply force times time.
00:56
The final velocity is zero.
00:58
And we're going to divide both sides by time to get forced by itself.
01:02
So for both of these, the equation will be force is equal to negative mass times velocity initial, excuse me, velocity initial, divided by time.
01:12
And so for the first one, it is negative 1700 times 24 divided by 1 .5.
01:21
And from that, we call this f1...