three blocks,each with same mass, stacked one upon the other. the bottom block rest on a frictionlesshorizontal surface and is being pulled by a force F that is parrallel to this surface.the surface where the blocks touch each other have identical coefficients of static friction. which one of the following correctly describe the magnitude of the net force of static frection that acts on each block?
(a)fs,A=fs,B=fs,C
(b)fs,A=fs,B=0,5fs,C
(c)fs,A=0 and fs,B=0.5fs,C
(d)fs,C=0 and fs,A =0,5fs,B
(e)fs,A=fs,C=0,5fs,B
To determine the correct answer, we can consider the forces acting on each block individually.
For the bottom block (Block C), it is being pulled by a force F. Since there is no friction on the horizontal surface, the only force opposing the motion of Block C is the static friction between Block B and Block C.
The static friction force will cancel out the applied force F, so the magnitude of the net force of static friction acting on Block C is zero.
Therefore, we can eliminate options (a), (d), and (e) as they imply that there is non-zero static friction on Block C.
Now let's consider Block A and Block B, which are stacked on top of Block C. Since all the blocks have the same mass and are stacked vertically, they experience the same gravitational force.
The maximum static friction force between two surfaces is given by the equation fs = μs * N, where μs is the coefficient of static friction and N is the normal force acting perpendicular to the surface.
Since the surfaces where the blocks touch have identical coefficients of static friction, the magnitude of the static friction force is the same for both Block A and Block B.
Therefore, the correct answer is option (b): fs,A = fs,C = 0.5fs,B. This means that Block A and Block C have half the net force of static friction compared to Block B.