Critical Force Block Rough Surface

As shown in the figure, a block of mass √3kg is kept on a horizontal rough surface of coefficient of friction 1∕3√3. The critical force to be applied on the vertical surface as shown at an angle 60∘ with horizontal such that it does not move, will be 3x. The value of x will be ...........[g=10ms−2;sin‌60∘=‌

√3

2

cos‌60∘=‌

1

2

]