Question

What is the minimum horizontal force that needs to be applied to the bottom block of mass M so that the top block of mass m slides off? The coefficient of friction between the bottom block and the floor is µ1, the coefficient of friction between the two blocks is µ2

Answer 1

acceleration of both = a
force forward on top block = u2 m g = m a
so a = u2 g

force forward on bottom block = F
force back on top block = u2 m g + u1(m+M)g
F - u2 m g - u1(m+M)g= (m+M) a = (m+M) u2 g
F = u2 m g +u1 m g +u1 M g + u2 m g + u2 M g
= u1 (m + M) g + u2 ( 2m + M)g

Answer 2

Thank you!!!!

Answer 3

You are welcome.