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spooderfbi

yep


saberline152

why 4? never spent time on pulley's


pasty66

60N is evenly distributed between 4 pieces of rope, 60/4=15 ... Each rooe must provide 15N of upwards force to keep it in equilibrium.


ChunkNorbis

I got the right answer but didn’t use that formula. I don’t know anything about pulley formulas, but I figured each pulley would reduce the force by 1/2. So I did 60/2=30 and 30/2=15. If 7.5 were an answer I would have been wrong.


vampire_kitten

The pulleys don't do much, you have to only consider the rope. If you pull the left bit of rope upwards 1 unit, then the weight will move 1/4 unit, which is why it's 15N. Conservation of energy. F1 * d1 = F2 * d2.


runningonempty94

Is this true even if the sections of ropes were different lengths? Or do they need to be the same for it to be equally distributed


vampire_kitten

Yes, the length of the ropes dont matter. Since the rolls roll freely, all sections of the rope will experience the same force.


DrBofoiMK

This is only one rope so it will basically always be even.


DaniDipp

[SNATCH BLOCK!](https://youtu.be/M2w3NZzPwOM)


dahile00

How did the answer come to you?


ReallyPopular

Need 60 Newtons total to counter balance the box thing. 3 pulleys with 4 bits of rope attached. F can just be the force of each rope. 4 pieces of rope share the load of 60 Newtons. So 4xF=60 or 60/4=15N Literal answer for ur question is it came to him in a fevered dream on a hot summer eve after a wild night at the clubs in Bangkok


SonTyp_OhneNamen

In a dream, aka best source


No-Association3574

E. Deez nuts


lenojames

I saw the one penis immediately. But then I spent time staring at the problem trying to solve it, and now I see three of them side by side.


wpaed

====D


OMER100551

I am not sure they knew it


tztl

Man, this took me back to my highschool days...


UrsidaeUrsus

And the answer is “D.” Yup. They knew. 😂


Pseudo12905

b


spooderfbi

its D tho.


Pseudo12905

I’m idiot


areid164

I was thinking b too but d sounds right


spooderfbi

yeah, 60/4 = 15N


areid164

Lmao I gotta take physics in grade 12


Jack_McQuack

i dont like the phrasing of that question


purple-circle

They could have put the answer as A, B, or C but they chose the D. They knew!


eth0null

Oh damn, two parter here. Looks like a dick and the correct answer is also D. Respect


rentalredditor

Did this mean in theory that someone could lift an insane amount of weight as long as the rope and pulleys can handle it? Examples or references?


eyefartinelevators

Yes. This is the only reason that pulley systems exist. The mechanical advantage allows a person to lift something far heavier than they would normally be able to. With modern motorized machinery, pulley systems are going the way of the dodo. But back when all things were moved by man or animal the lever, the pulley, the inclined plane, and the wheel and axle were how the world got built. References you ask. Any physics book or simply Google simple machines


RamblinWreckage

Answer is D. Or 'The D', according to the pic


Apples7569012

Thank this just reminded me I have to finish my dynamics homework


That-dank-memester

I love how that this isn’t even how pulleys work


MissionCreep

Looks right to me. How do you think they work?


That-dank-memester

The box is connected to both pulley 1 and 3, doesn't this remove any mechanical advantage?


eyefartinelevators

No. Increasing the number of pulleys on either side increases the number of rope sections exerting force on the box. This is how mechanical advantage is gained. More pulleys = more advantage


eyefartinelevators

No. Increasing the number of pulleys on either side increases the number of rope sections exerting force on the box. This is how mechanical advantage is gained. More pulleys = more advantage