Angle of repose is defined as the minimum angle made by an inclined plane with the horizontal such that an object placed on the inclined surface just begins to slide.

#### Relation between Angle of Friction and Angle of Repose

Let us consider a body of mass ‘m’ resting on a plane.

Also, consider when the plane makes ‘θ’ angle with the horizontal, the body just begins to move.

Here,

mgsinθ = -F ——> (i)

mgcosθ = -R ——>(ii)

Dividing equation (i) by (ii)

Or, Tanθ = µ, where ‘µ’ is the coefficient of friction

Or, Tanθ = Tanɑ (tanɑ = µ)

where ‘ɑ’ is the angle of friction

**θ = ɑ**

Angle of repose is equal to angle of friction.