A block of mass `4 kg` is pressed againest the wall by a force of `80N` as shown in figure Determine the value of the friction force and block's acceleration (Take `mu_(s) = 0.2 , mu_(s) = 0.15)`

Answer

8

Explanation

`F_(smax) = muN = 0.2 xx 64 = 12.8N`
Net applied force parallel to contact surface `= 48 - 40 = 8`
`N("upward")`
`:' F_("applied") lt f_("smax")`
`:.` Friction force `= 8N`