Tension between 2 blocks and friction.

AI Thread Summary
A block system consisting of two masses (m1 = 2 kg and m2 = 3 kg) is pulled by a force of 25 N, with a friction coefficient of 0.14. The calculated acceleration of the system is approximately 3.6 m/s². The total frictional force acting on the blocks is 6.867 N, with individual frictional forces of approximately 2.7468 N for m1 and 4.1202 N for m2. The tension in the string between the blocks was ultimately found to be 10 N after resolving the forces. The discussion highlights the importance of free body diagrams and accurate force summation in solving for tension in such systems.
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Homework Statement



hm4.gif


A block of mass m1 = 2 kg and a block of mass m2 = 3 kg are tied together and are pulled from rest across the floor by a force of P = 25 N. The coefficient of friction of the blocks with the floor is µ = 0.14.

I found the acceleration to be 3.6266 m/s2.

I need to find the tension in the string between the blocks.

Homework Equations



F=ma and Ff=u(mg)

The Attempt at a Solution



The total frictional force is 6.867 N. m1 has a frictional force of 2.7468 i think, and m2 has a frictional force of 6.7596 i think. I think the pulling force on m1 is 7.2532 N. I mean, i tried creating different summations of the forces, but I don't know what I'm doing wrong. I'm sure I could figure it out, but I need to at least know how to add the forces up in each direction. Thanks so much.
 
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CaptainSFS said:

Homework Statement



hm4.gif


A block of mass m1 = 2 kg and a block of mass m2 = 3 kg are tied together and are pulled from rest across the floor by a force of P = 25 N. The coefficient of friction of the blocks with the floor is µ = 0.14.

I found the acceleration to be 3.6266 m/s2.
Good. You should round it off though to 3.6

The total frictional force is 6.867 N.
yes
m1 has a frictional force of 2.7468 i think,
yes
and m2 has a frictional force of 6.7596 i think.
where did you get this?
I think the pulling force on m1 is 7.2532 N.
how did you arrive at this?
I mean, i tried creating different summations of the forces, but I don't know what I'm doing wrong.
Draw a Free Body Diagram of block 1 (isolate it) , and examine the forces acting on it to solve for T using Newton 2. What is the acceleration of block 1?
 
okay, I typed the wrong number in for m2's frictional force. I meant to type in 4.1202 N. I arrived at m1's pulling force by (2)(3.6) = F. Right, I thought I tried creating a FBD but for some reason I'm doing something wrong. Is the acceleration on block m1 = 2.25 m/s2? At this point I am not sure what I am supposed to do.

EDIT: wait, doesn't the acceleration have to be equal to 3.6m/s2?
 
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Hey, if someone could help me. I'm really stuck on this one, I just think I've dug myself a deeper hole trying to work this out. I would really appreciate any more help.

EDIT: I solved it. it's 10 N...
 
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Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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