00:01
In this problem, we have two blocks being held together by a pulley system.
00:04
And we want to find the speed of each one when block b falls 1 .5 meters.
00:14
So we know that the mass of a is 20 kilograms and the mass of b is 30 kilograms.
00:27
So that means b, block b will be going down and block a will be going down.
00:34
We'll be going up, so we'll be going in opposite directions.
00:38
Block a has a three -poly system, so we can say three times the distance of each little pulley, which will call s -a plus the length of the pulley on b.
00:54
We'll call s -b will equal to total length of the whole pulley system.
01:01
We take the difference of each, we have three, delta, s a plus delta sb and the difference of the total length is zero and if we divide by delta t for each we get three delta s a divided by delta t plus delta s b delta t equals zero these are actually velocities so if we move this to the right we can say three velocity a equals minus negative velocity b.
01:48
So now we have an equation to find both velocities.
01:52
We find one, we can find the other...