The force P is applied to the $32-$kg block when it is at rest. Determine the magnitude and direction of the friction force exerted by the

surface on the block if $($a$)$P$=0,($b$)$P$=155$N$,$ and $($c$)$P$=228$N$.($d$)$ What value of P is required to initiate motion up the incline? The

static and kinetic coefficients of friction between the block and the incline are $\backslash$mu $\_($s$)=0\mathrm{.}30$ and $\backslash$mu $\_($k$)=0\mathrm{.}24,$ respectively. The friction force is

positive if up the incline, negative if down the incline.

Answers:

$($a$)$ F$=$

N

$($b$)$ F$=$

i N

$($c$)$ F$=$

i

N

$($d$)$ P$=$

:$\text{'}$N