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)`

Options

A. `8 N,0ms^(-2)`
B. `32 N,6 ms^(-2)`
C. `8 N,6ms^(-2)`
D. `32 N,2ms^(-2)`

Answer

a

Explanation

The FBD of the block is as shown in figure

` N = 80 cos 37^(@) = 64 N`
`so , f_(L) = 0.2 xx 64 = 32 N`
As `4 kglt 80 sin 37^(@)` friction will act doiwnward net applied force in upward direction (excludding friction force) is
`80 sin 37^(@) - 40 = 48 - 40 = 8 N`
As `F_(applied)` in vertical direction and value of static friction force is `f = 8 N`