A wooden block is observed to slide across a horizontal laboratory table at a…
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A wooden block is observed to slide across a horizontal laboratory table at a constant speed after an external horizontal force is applied.
Assume the only horizontal forces acting on the block are the applied force and kinetic friction. The block remains on the same horizontal surface throughout the motion.
(a) Explain, in words, why the speed of the block remains constant once it is sliding, even though a kinetic-friction force acts on it.
(b) Describe qualitatively how the magnitude of the normal force affects the magnitude of the kinetic-friction force in this situation. Include in your discussion what would happen to the kinetic-friction force if the table were tilted slightly upward while the horizontal pulling force remained the same.