## Engineering Mechanics: Statics & Dynamics (14th Edition)

$16.67N$
We know that when Block B starts moving, then $P-\mu g=0$ We plug in the known values to obtain: $P-0.3(10)(9.81)=0$ $\implies P=294N$ When Block B starts rotating about P, then $\Sigma M_P=0$ $\implies 10\times 9.81\times 0.15-P\times 0.40=0$ $\implies P=36.8N$ Similarly, when A starts moving, then $P-(0.1)(17\times 9.81)=0$ $\implies P=16.67N$ This is the required force which is applied to the cord without causing motion.