## shubhamsrg 2 years ago coefficient of friction between the 2 blocks is U and the surface below the bigger block is smooth . Find the min and max force that can be applied in order to keep the smaller blocks at rest with respect to the bigger block.

1. shubhamsrg

|dw:1356948181967:dw|

2. shubhamsrg

|dw:1356949501640:dw| is that right ?

3. yrelhan4

sorry.. this is right! missed the pseudo on second small block..

4. Vincent-Lyon.Fr

This problem was already solved on OS. Will try to find the reference.

5. shubhamsrg

eqns of motion would be Umg + m(F/M) = T and T + Um(F/M) = mg => Umg + m(F/M) + Um(F/M) = mg the value of F that am getting is not right ! ;)

6. sauravshakya

|dw:1356961990631:dw|

7. sauravshakya

Sorry that case was when it tends to move to the right

8. sauravshakya

Now, |dw:1356962249332:dw|

9. sauravshakya

Fr1= umg Fr2 =umF/(M+2m)

10. sauravshakya

F' = mF/(M+2m) W=mg

11. sauravshakya

From W-Fr2-F'-Fr1=0 we get F=g(M+2m)(1+u)(1-u) From F'-mg-Fr2-Fr1=0 we get F =g(M+2m)(1+u)/(1-u)

12. shubhamsrg

i see!! thanks a lot! that helped !

13. shubhamsrg

i understand it now..