we are one last time talking about Newton's first law time by first of all let's look at the weights here these are four bricks equal size bricks equal mass and they are held up by scales this one has three scales and three ropes holding up it has one real going scale and two scales or two rows and two scales both attached on the same rope holdin up now the question is which of these will have the greatest tension on the rope and more ropes are attached to an object that means that the force of the object to say these bricks weigh 10 Newtons okay and that means when there are three different scales the weight will be split evenly between these so we have three point three here and three point three here and three point four here and so the weight would be scattered across those three ropes if there are two ropes like this and each one would have a had to pull upward with the force of 5 Newtons because we know that the weight of the brick is going down at 10 News so they Eve would have to pull up as well as continue to bring down and come out and having it a net force is zero and therefore the things hanging there if there is one rope then we know this rope I'll attend to know 10 Newtons okay because there's a force of 10 Newtons pulling down on it rope is pulling up attending and therefore the net force is zero and the brick will stay suspended hanging on the rope all right now when you have this one you still have 10 Newtons pulling down on it and since you have one rope it would also be 10 Newton's pulling up now if the second scale weight more then you could argue if there's a greater mass anymore because of a number of scales we're not really considering the mass of scales in this we're not going to worry about that so basically we would say which rope has the greatest force F or tension on it there would be B and B equal they both have tendons that matter bring attention on the road as whereas these other ones the two has split it in five piece and then three a third a third and a third you were taking a little bit to come back to ten all right now at similar kind of situation would exist if you were ice aboard here on the scale if he's saying both scale let's just say if the boy has a mass of 200 news it's only about 50 pounds let's protect okay and if he's standing on both scales equally for the balance and grace and we would expect one fail to read about 100 and the other scale to read about 100 and if you put those two together then you have a force of they would be pushing up with a force of 200 Newtons he's waiting for that and we would have in that force is zero which is why standing there now if he leans over on one side he's still pushing down within that force of or a for sashimi of 200 news his weight stays the same however we would expect this side maybe to go up to saying I have 50 meters anymore way over for from that buddy whereas this side my only 50 but notice it's a little amount of force it's still the same so we have a 200 Newton force pushing up to a Newton force pushing down and we still have a net force of zero in our equilibrium there are other examples words if we look at the girl hanging from employee once again she has two ropes that are supporting her weight and so her weight would be half on one and half on the other if she had a scale here it would measure the tension this one sided it would be half of her weight we could also do the same thing with someone swinging on a trapeze as long as it's equal then each of these would ropes would have attempts in there to equal to half of the weight of the girl if she leans harder on one side then we would expect it to be more than that but the total force on the to go for that up to the weight of a little girl all right now if we go off one last thing a couple things let's look at real quick ah this one here there's probably a book that talks about this book basically if we know that the painter Frank here had the mass of 500 Newtons and he has two ropes that are tied to his swing bosun Cherico distance one person's foot chair and so each of these ropes would have attention of 250 on each one which we gave in that fortune zero which means he's held up in the air now unfortunately this rope can only hold 300 Newtons and so in this case it's alright because each of the two ropes attached to Frank's care are doing a 250 which puts them below go 300 Newton limited they can support however if he ties off his rope to a flagpole and now there's only one rope attached to this chair we know that Frank weighs 500 so the tension on that one rope is also going to be 500 and that's what's happening to bring pretty quickly this rope is going to break any of your going to go falling down splats and he's gonna be on workmen's compensation because he will not be there to work anymore because the net force is no longer zero once the rope snaps there's 6,500 Newton's force pushing down nothing to balance it anymore because the troponin has Simpson pulling up on it and he is crashing down below all right that's all that now another type of problem is going to get is a kind of scaffold I paint your scaffold and basically in this scaffold we have forces pushing down which would be the weight of the objects let's just say that's 1 over 100 and this one over here able to say make it easy and also 100 all right and we're going to say there is a force of 200 on this rope up at the force of 200 and I fake one over here and also forced to you Andre okay now if we know the sample is not going anywhere we know if the net force must be 0 okay so we know there's 200 force 100 here 100 here the weight of the two painters pushing down and there's 400 pushing up so since it's not going anywhere there needs to be another 200 meters to balance that and that would tell us that this board here must have a mass of 200 Newtons now that's probably a really heavy board unless it's made out of iron or something like that but at any rate that's what we tell any time we have a scalpel is sitting there we know that the force is pulling up the tension on the ropes must equal to the weight or the force pushing down on the scaffold which leaves the board and the two painters all right now if one of the painters would start walking toward the other end then instead of being 200 and 200 this and now has more force pushing on it so it might go up to say a300 okay and the one over here would only have now as you get further wasting less fortunately so it might only have 100 but notice there's still an upward tension of 400 meetings and you've said that the two painters and board putting four hundred Newton's down and so it's still at equilibrium and finally it may go off to completely the other end right now you have maybe say three hundred and ninety over here okay and maybe only ten Newton's over here but still its net force is zero because we're under pushing down the tension in the ropes equals four hundred pulling up and they stay motionless because in that force is zero therefore they are not going to be following and moving and changing their momentum well to help you out see you later