Four identical blocks are moving on a surface for which the coefficient of kinetic friction between each block and the surface is µ_k. The velocity of each block is indicated by the vector on the block. For which block is the force of friction between the surface and the block greatest? A) 1 B) 2 C) 3 D) 4 E) The force of friction is the same for all blocks.

Question

Quizplus · Accepted Answer

The force of friction on each block will be equal and opposite to the force applied on it to cause its motion (Newton's Third Law). Since all the blocks have the same mass and coefficient of friction, and are moving with the same speed, the force of friction will be the same for all four blocks. Therefore, the answer is E.

Four Identical Blocks Are Moving on a Surface for Which