Block A of mass 100 ~kg is kept above another block B of mass 300 ~kg . A is tied to the wall C with a horizontal string. The coefficient of friction between A and B is 0.35 and that between B and the horizontal surface is 0.5 . Find the horizontal force p , necessary to move the block B .

Step-by-step solution

Given, the coefficient of friction between A and B, ₁=0.35 The coefficient of friction between B and surface, ₂=0.5 Mass of block A, m_a=100 ~kg Mass of block B, m_b=300 ~kg Frictional force between blocks A and B , aligned f₁ & = ₁ m_a g & =0.35 100 9.8 & =0.35 980 & =343 ~N aligned Frictional force between block B and surface, aligned f₂ & = ₂ (m_a+m_b ) g & =0.5(100+300) 9.8 & =0.5 4 980=1960 ~N aligned Minimum force required to move block B , array rlrl & & F & =f₁+f₂=343+1960 & & =2303 ~N array Which is neares