Halliday, Resnick & Walker — Force and Motion–II: Problem 5_E_GO

A 2.5 kg block is initially at rest on a horizontal surface. A horizontal force \(\vec{F}\) of magnitude 6.0 N and a vertical force \(\vec{P}\) are then applied to the block (Fig. 6.6). The coefficients of friction for the block and surface are \(\mu_s = 0.40\) and \(\mu_k = 0.25\). Determine the magnitude of the frictional force acting on the block if the magnitude of \(\vec{P}\) is (a) 8.0 N, (b) 10 N, and (c) 12 N.