일반물리학 1 — Force and Motion-II: Problem 9

9 A 3.5 kg block is pushed along a horizontal floor by a force \( \vec{F} \) of magnitude 15 N at an angle \( \theta = 40^\circ \) with the horizontal (Fig. 6-17). The coefficient of kinetic friction between the block and the floor is 0.25. Calculate the magnitudes of (a) the frictional force on the block from the floor and (b) the block’s acceleration.