JEE Main 2021 · 24 Feb · Shift 1, Physics question 25

An inclined plane is bent in such a way that the vertical cross-section is given by $y=\dfrac{x^2}4$ where y is in vertical and x in horizontal direction. If the upper surface of this curved plane is rough with coefficient of friction μ = 0.5, the maximum height in cm at which a stationary block will not slip downward is _______ cm.