In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
A block of mass 4 kg rests on a rough horizontal plane. The coefficient of friction between the block and the plane is 0.5.
A force of magnitude P P\,P newtons is applied to the block at an angle θ \theta\,θ above the horizontal, and the block is on the point of moving.
Show that P=2gcosθ+0.5sinθ\displaystyle P = \frac{2g}{\cos\theta + 0.5\sin\theta}P=cosθ+0.5sinθ2g.
Find the value of θ \theta\,θ for which P P\,P takes its least value, and find that least value of PPP.