A_Level_Student 3 years ago A horizontal force of 20N just prevents a mask of 2kg from sliding down a rough plane inclined at 45 degrees to the horizontal.Find the coefficient of friction.

1. hosein

Hi from below fig we can analyze forces and solve question: |dw:1333139120501:dw|

2. hosein

analyze forces respect to this coordinate |dw:1333139185052:dw|

3. A_Level_Student

i have a similar diagram but how can we analyse the forces

4. hosein

so:in direction of normal to incline:$N-Fsin \theta =mgcos \theta$& in direction of down of incline:$mgsin \theta-Fcos \theta-\mu _{s}.N=ma=0$so if you solve 2 equation for mu yields:$(-Fcos \theta+mgsin \theta)/(Fsin \theta+mgcos \theta)=\mu _{s}$

5. salini

hey hi! u draw the diagram again with the resolving of vectors can u do that? wat is ur name?

6. hosein

u oght be analyze forces respect to that coordinate |dw:1333221355385:dw|

7. salini

bisho, were u comfortable in resolving those horizontal force and mg down the slope?

8. A_Level_Student

|dw:1333350119161:dw|

9. salini

|dw:1333455525796:dw| |dw:1333455661277:dw| where Ff is frictional force sum up all these forces acting on the body i have shown different diagrams to avoid confusion i want the body to be in rest so all those vertical forces (on bothe sides of incline) and horizonatal forces(acting on both sides shud be equal)