Two blocks are stacked one on top of the other. The coefficient of friction between the two blocks is 0.20, and the coefficient of friction between the bottom block and the floor is 0.10. What is the max force you can apple to the bottom block such that the top block does not slide off?

Top block mass = 1.0 kg
Bottom mass= 3.0 kg

1 answer

Is the 0.20 a static friction coefficient? Is the 0.10 a kinetic friction coefficient? Those are the types you need to solve the problem.

First calculate the maximum friction force (Ftop) that the top block can withstand without sliding.

M(top)*g *0.2 = Ftop

Then calculate the max applied force to the lower block, Fmax

Fmax - Ftop - (Mtop + Mbottom)*0.1 g= (Mbottom + Mtop)*a

where

a = Ftop/Mtop