• On assuming the block lies stationary, we have (1 × cosθ ) = mgsinθ = (1 × sinθ ) ⇒ θ = 45° • If θ > 45°, we have (1 × cosθ ) < mgsinθ That is, the friction acts upwards on the block thereby keeping the block in stationary position. • At θ < 45°, we have (1 × cosθ ) > mgsinθ That is, the friction acts downwards on the block thereby bringing down the block.