a. Block A , as shown in figure weight `60.0 N` The coefficient of static friction between the block and the surface on which it rest is `0.25` .The system is in equlibrium .Find the friction for excerted on block A
b. Find the maximum weight w for which the system will remain in equlibrium

Explanation

For an angle of `45.0^(@)` , the tension in the horizontal and vertical wires will be the starts
a. The tension in the vertical wire will be equal to the weight `w = 12.0 N` This must be the tension in the horizontal wire , and hence the friction force on blockA is also`12.0 N`
b. The maximum friction force is
`mu_(s) w_(A) = (0.25)(60.0 N) = 15 N` This will be the tension in both the horizontal and vertical parts of the wire , in the maximum is `15 N`