Entries by kuruman

Frames of Reference: A Skateboarder’s View

My essay Explaining Rolling Motion raised some commentary about frames of reference and their equivalence when solving physics problems. I wish to pursue the idea of shifting one’s frame of reference because its use is relatively uncommon in introductory physics courses.   Students are asked to solve problems mostly in the (approximately) inertial frame of […]

Explaining Rolling Motion

Although rolling wheels are everywhere, when most people are asked “what is the axis of rotation of a wheel that rolls without slipping?”, they will answer “the axle”.  It is an intuitively obvious answer shared by 3/4 or more of the students in an introductory physics class.  It is also the wrong answer.  Here I […]