LOG#042. Pulley with variable mass.

This interesting problem was recently found in certain public examination. I will solve it here since I found it fascinating and useful, since it is a problem with “variable mass”. A pulley with negligible mass is given (see the figures … Continue reading

LOG#026. Boosts, rapidity, HEP.

In euclidean two dimensional space, rotations are easy to understand in terms of matrices and trigonometric functions. A plane rotation is given by:     where the rotation angle is , and it is parametrized by . Interestingly, in minkovskian … Continue reading