Equilibrium: a Dump Truck Has a Large Cubical Concrete Block

Multiple Choice

Equilibrium: A dump truck has a large cubical concrete block in its bed. The coefficients of friction between this block and the floor of the bed are µ_k = 0.450 and µ_s = 0.650. As the bed is slowly tilted above the horizontal, will the brick first begin to slide or will it first tip over?

A) It will first tip over.
B) It will first begin to slide.
C) It will tip over just as it begins to slide.
D) It is impossible to answer without knowing the mass of the block.
E) It is impossible to answer without knowing the dimensions of the block.