Khan Academy Static

You're traveling toward me at half the speed of light. My friend is traveling away from me at half the speed of light. From either of your points-of-view, how quickly are you approaching each other? Things are going to get even more fun now. We're going to think about relative velocities in different frames of reference.

10228_Calculating_neutral_velocity.html

10227_Finding_an_in_between_frame_of_reference.html

10224_Lorentz_transformation_for_change_in_coordinates.html

10225_Einstein_velocity_addition_formula_derivation.html

10226_Applying_Einstein_velocity_addition.html

10229_Time_dilation.html