What is the maximum value of the force F such that the block shown in the arrangement does not move [2003]
(1)
Since the block is not moving forward for the maximum force F applied, therefore
Fcos60°=f=μN
(Horizontal direction)
For vertical equilibrium of the block,
N=mg+Fsin60°
∴ Fcos60°=μN=μ(Fsin60°+mg)
⇒F=μmgcos60°-μsin60°=123×3×1012-123×32=514=20 N