Question Detail
Question
A block is pulled at a constant speed across a horizontal surface by a horizontal rope. The tension in the rope is 25 N. What is the kinetic friction force acting on the block?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Since the block is moving at a constant speed, its acceleration is zero, so the net force on it is zero. Therefore, the pulling force (tension = 25 N) must be exactly balanced by the kinetic friction force, which is also 25 N.
Hint
Apply Newton's first law: constant velocity implies zero net force.