Changes

The length, <math>l</math>, of an object as seen by a (relative) stationary observer is given by:

The length, <math>l</math>, of an object as seen by a (relative) stationary observer is given by:

<math> l = l_{0} \sqrt{1- \frac{v^{2}}{c^{2}}}</math>

<math> l = l_{0} \sqrt{1- \frac{u^{2}}{c^{2}}} = \frac{l_0}{\gamma}</math>

Where  

Where  

:<math>l_0</math> is the "proper length" or the length of the object in the observed frame of reference.

:<math>l_0</math> is the "proper length" or the length of the object in its own [[inertial frame of reference|frame of reference]].

:<math>v</math> is the relative velocity between the reference frames.

:<math>u</math> is the relative velocity between the reference frames.

:<math>c</math> is the speed of light (3x10⁸ ms^-1).

:<math>c</math> is the speed of light (<math>3 \times 10^8 </math> m s^-1

===Mass increase===

===Mass increase===