00:01
So in this problem, we have two running to each other.
00:08
We have a 100 kilogram tackler that is moving at 2 .5 meters per second.
00:15
And it meets heads -on to a 282 kilogram that's moving at 5 meter per second.
00:25
It's a head -on collision, so they should be in opposite direction.
00:30
And then they collide together and they hold on to each other so now they become just one huge mess moving together and we're trying to figure out how this moves so firstly let's decide a positive direction because things they are moving in opposite directions one will have a positive velocity and one will have the negative velocity and let's just call this positive so then let's call the tachler a and the half back so now we have ma equals the mass of the tackler is 110 kilogram and the velocity is 2 .5 meter per second.
01:13
For halfback we have mb equals 82 kilogram and its velocity is negative since it's moving opposite direction.
01:24
So this is what happens and this is all before collision.
01:28
So we call initial.
01:31
What about final that is after collision? after collision, there is really just this one huge mass because they hold on to each other so we can sync of them as a whole and that is just one 92 kilogram.
01:44
Now we are looking for the vast speed.
01:48
And in section two, all we need to know is the conservation momentum, which means for any isolated system without external forces, the momentum will be the same before and after the collision.
02:02
And this is the equation we'll be needed here.
02:05
Before the collision, the momentum is just, the total momentum is the addition of their separate momentum, plus m -d -v -b...