00:03
Okay, we've got a crate hanging from these two ropes that are at different angles here.
00:11
And we know the tension in the ropes.
00:13
And we want to use that to find the weight of the crate in newtons.
00:24
So let's think about what's happening at this point right here.
00:31
Do i have enough space? okay, i'll put it about here.
00:36
So that's that point right there.
00:38
So the crate is pulling down with its weight.
00:45
Let's just call that c for crate.
00:48
Then the ropes are pulling at these angles, one like this and one like this.
00:55
Let's say, okay, so since nothing is moving, this crate is just hanging there, not moving, we know that all these forces are going to balance because if there was a net force in one direction or another, then the crate would have to move, but it doesn't.
01:18
So let's break these forces down into their x and y components.
01:25
So c is acting totally along the y -axis, but the rope forces are not.
01:36
So i could break this one down into some x -direction force and some y -direction force.
01:47
And then same thing here, some x -direction force and some y -direction force.
01:54
So since c is only in the y -direction, we know that the sum of these two, maybe i'll call this one f, let's just call it f1y, i guess, and then this one will be f2y.
02:18
So i know that c is equal to the sum of those two in order for those forces to balance.
02:30
Okay, so let's see if we can figure out what they are...