Hi, I have a forces problem involving a pulley, I think I'm almost there. I was wondering if anyone may please give me some suggestions on how to solve this. Thank you.(adsbygoogle = window.adsbygoogle || []).push({});

Diagram:

Question: Three boxes are connected by cords, one of which wraps over a pulley having negligible friction on its axle and negligible mass. The masses are [tex]m_A=30.0kg[/tex], [tex]m_B=40.0kg[/tex], and [tex]m_C=10.0kg[/tex]. When the assembly is released from rest, what is the tension in the cord connecting [tex]B[/tex] and [tex]C[/tex].Code (Text):

_____

| |

| A |______________

_|_____|______________O\

/ |

| |

| _|_

|| | B

||___|

| |

| _|_

|| | C

|| |

||___|

I've started the problem by treating mass B and C as one big mass and drawing free body diagrams.

For mass A: [tex]F_{net}=F_{T_{sys}}=m_Aa_{sys}=30a_{sys}[/tex]

[tex]a_{sys}=\frac{F_{T_{sys}}}{30}[/tex] (1)

For the "big mass" (mass B + mass C):

[tex]F_{net}=F_g-F_{T_{sys}}=50a_{sys}[/tex]

[tex]a_{sys}=\frac{50g-F_{T_{sys}}}{50}[/tex] (2)

Solving for [tex]F_{T_{sys}}=183.75N[/tex] and [tex]a_{sys}=6.125m/s^2[/tex]

Now how can I used this information to find the tension between mass B and C?

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# Homework Help: Pulley Question

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