Grindstone

A uniform cylindrical grindstone has a mass of \({{ params_M }} \rm{kg}\) and a radius of \({{ params_R }} \rm{cm}\).

Part 1

What is the rotational kinetic energy \(K\_{\text{rot}}\) of the grindstone when it is rotating at \({{ params_RPM }} \rm{rev/min}\)? You may assume that the grindstone is a solid cylinder rotating about its cylinder axis.

Answer Section

Please enter a numeric value in \(\rm{J}\).

Part 2

After the grindstone’s motor is turned off, a knife blade is pressed against the outer edge of the grindstone with a perpendicular force of \({{ params_F }} \rm{N}\). The coefficient of kinetic friction between the grindstone and the blade is \({{ params_mu }}\). Use the work energy theorem to determine how many turns \(N\) the grindstone makes before it stops.

Answer Section

Please enter a numeric value.

Attribution

Problem is from the OpenStax University Physics Volume 1 textbook, licensed under the CC-BY 4.0 license.