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Mechanics question AS level help please

I am trying to find "a" in a question and I have gotten as far as:

T1 = [mg - (√3 x ma)]/2
T2 = (2mg x T1)/√3

I was told by a teacher to sub in 0 for T1 and T2 to get 2 answers for "a", but because I don't know "m" I don't know how that helps?

Any help of where to go next would be appreiciated, thanks! Let me know if you need any more information about the question to help.

Reply 1

Shaanv

Whats the question? Can u post a picture?

Reply 2

ookatiebourneoo

Original post by Shaanv

Whats the question? Can u post a picture?

There you go, that's the questions (I am on part b) and the work I have done so far. Thank you! <3

Mechanics 1.jpg63.0KB

Mechanics 2.jpg77.1KB

Reply 3

Shaanv

Original post by ookatiebourneoo

There you go, that's the questions (I am on part b) and the work I have done so far. Thank you! <3

I cant see the picture properly on my mobile, but i assume that u have expressions for the tension in each string.

For a string to go slack there has to be no tension in the string, so u can find the acceleration needed to make each string go slack. By solving when T=0

(edited 6 years ago)

Reply 4

ookatiebourneoo

Original post by Shaanv

Yes that's it! But how do I solve for T=0 with the equations that I provided in the original question as I don't know the mass?

Reply 5

Shaanv

Original post by ookatiebourneoo

Yes that's it! But how do I solve for T=0 with the equations that I provided in the original question as I don't know the mass?

The masses should cancel out if I’m not mistaken.

In BC, T=0.5mg-0.5am(root 3)

When T=0, 0.5mg=0.5ma(root 3).

Can u see how mass cancels out?

Reply 6

ookatiebourneoo

Original post by Shaanv

The masses should cancel out if I’m not mistaken.

In BC, T=0.5mg-0.5am(root 3)

When T=0, 0.5mg=0.5ma(root 3).

Can u see how mass cancels out?

Yes I can see that, thanks! How do I do that for the T2 equation? Do I sub in the equation for T1? I am stugglign subbing it in then cutting down the eqation to get "a=".

Reply 7

Shaanv

Original post by ookatiebourneoo

Yes I can see that, thanks! How do I do that for the T2 equation? Do I sub in the equation for T1? I am stugglign subbing it in then cutting down the eqation to get "a=".

U have resolved horizontally to get an equation relating t1 and t2 so u can substitute in ur t1 equation, then make t2 equal to zero and rearrange. U should be able to reduce it down to find the acceleration.