Two blocks placed one on top of the other are lying on a horizontal smooth surface. The coefficient of friction between the blocks is [tex]\mu[/tex]. Case 1: Horizontal force F is applied to the lower block (Fig. 14). [PLAIN]http://www.monbattle.com/1.jpg[/CENTER] [Broken] Please help me to find out how they have got those equations. I'm trying to find it from past several hours but couldn't got any hint.