# What is the tension in the cord connecting the two blocks at this instant?

1. Feb 24, 2010

### huybinhs

1. The problem statement, all variables and given/known data

The coefficient of static friction between block A and a horizontal floor is 0.45 and the coefficient of static friction between block B and the floor is 0.30. The mass of each block is 2.0 kg and they are connected together by a cord.

What is the tension in the cord connecting the two blocks at this instant?

2. Relevant equations and 3. The attempt at a solution

as the friction force on the block A is 8.82 N, for just to move it the force is 8.82 N and this is applied by the cord only. Hence the tension in the cord is 8.82 N

2. Feb 24, 2010

### tiny-tim

Hi huybinhs!

At what instant? You haven't said what is happening to the blocks.

3. Feb 24, 2010

### huybinhs

Part a for this problem is "If a horizontal force F pulling on block B is slowly increased until it is barely enough to make the two blocks start moving, what is the magnitude of F at the instant they start to slide?"

4. Feb 24, 2010

### tiny-tim

ahhh!

ok then, the acceleration of the second block is zero, so just balance the forces on the second block.

(or the first block … same result … just takes a bit longer )

5. Feb 24, 2010

### huybinhs

Ok. Thanks! My answer is CORRECT, my instructor just fixed it. Thanks anyway ;)