# Your mass does not matter when sliding

**Question**

On a rough inclined plane. The force between two blocks is zero if:

- !!mu_1 > mu_2!!
- !!mu_1 < mu_2!!
- !!mu_1=mu_2!!
**Solution**

The only possible way there is force between the two is if the !!m_2!! is moving slowly than !!m_1!!.

We assume that they start from rest, so they have same initial velocity, so everything comes down to just acceleration since !!v=u+at!!

The acceleration of any block on the inclined plane is given by !!a = gsintheta-mugcostheta!!

So the relation would be !!gsintheta-mu\1gcostheta<=gsintheta-mu\2gcostheta!!

!!=>m_2<=m_1!!

So !!A, C!!