A wooden block is allowed to slide down the same smooth incline in two separate…
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Work Energy and Power · Work Energy and Power
Problem
A wooden block is allowed to slide down the same smooth incline in two separate trials – first on a highly polished surface (practically friction-less) and then on a surface coated with fine sand that offers noticeable friction. The block is released from rest from the same height in both trials.
(i) Define a conservative force and give one example. Define a non-conservative force and give one example.
(ii) State whether the work done by kinetic friction between two solid surfaces depends on the path followed. Give a brief reason.
(iii) Explain qualitatively why the block reaches the bottom with a lower speed in the second trial compared with the first, even though it starts from the same height.
(iv) Where does the mechanical energy that is "lost" in the second trial go? Describe the form in which this energy appears.