JOURNAL O F CHEMICAL EDUCATION TRIGONOMETRIC FORM OF THE LORENTZ TRANSFORMATION
Joseph R. Killelea Iona College, New Rochelle, N. Y. CALCULATIOAS involving the various Lorents transformations may he materially shortened by employing a trigonometric device for the evduatian of the term (1- vP/eP)'/~, ahichmay he rearranged to (el - v2)'/*//c. Consider a right triangle having base LI (velocity of translation) and hypotenuse e (velocity of light), calling the angle included between u and e the angle A. The third side is ( e l - v a ) ' / * . From the triangle it is evident that sin A = (c2- v ~ ) ' / P / cand that cos A = V / C , SO that
Suppose, far example, it is desired to calculate the mass of a moving particle from the Einstein equation m = mo/(l
- v2/c2)'/>.
Making the trigonometric substitution, it is only necwary to find the angle whose cosine is o/c and divide the rest mass by the sine of the latter angle to determine the relativistic mass.
