Newton's 3rd Law (Pulleys - 1)

[HydroMarioUSA]

Hi, I'm new here. Could someone provide some guidance on how to start this problem?

 

[HydroMarioUSA]

Apparently, it's against the rules to just ask for answers, but could someone tell me where to start?

 

[Biker]

Hello, Welcome to physicsforums .Yes, It is against the rules to give direct answer. We can only give where to start from and the rest is on you.

Massless means that the tension is the same along the string. So what you need to do is to get the free body diagram for each block. Try to find the tension in T3 and T2 then get m2

 

[HydroMarioUSA]

How do you get m2 from knowing T3 and T2, sorry if it's obvious?

 

[Biker]

How do you get m2 from knowing T3 and T2, sorry if it's obvious?

What do you get from analyzing the forces on M2?

 

[HydroMarioUSA]

Net force, right?
OH I see thanks!

 

[HydroMarioUSA]

Would T3 = Fg on m3 and T2 = Fg on m2 + Fg on m3? Is that how it works?

 

[Biker]

Would T3 = Fg on m3 and T2 = Fg on m2 + Fg on m3? Is that how it works?

Yes, That Fg on m3 comes from the tension in T3 it pulls up m3 and pulls downward on M2 so that M2 can pull it up :)

 

[HydroMarioUSA]

Is the answer (D)? The way I got it was by knowing that T1 = 182.28, and subtracting that by the forces of gravity on T1 and T3, then finally dividing that by 9.8...

 

[Biker]

Is the answer (D)? The way I got it was by knowing that T1 = 182.28, and subtracting that by the forces of gravity on T1 and T3, then finally dividing that by 9.8...

Yes the answer is D.