Recent content by scottJH

Homework Statement In a particular inertial frame of reference, a particle with 4-velocity V is observed by an observer moving with 4-velocity U. Derive an expression for the speed of the particle relative to the observer in terms of the invariant U · V Homework Equations...

Homework Statement In a particular frame of reference a particle with 4-momentum ##P_p## is observed by an observer moving with 4-momentum ##P_o##. Derive an expression for the speed of the particle relative to the observer in terms of the invariant ##P_p.P_o## I am completely stuck on this...

Thanks for all your help. I managed to solve it.

Is the angle still not valid if we consider the frame where particle A is stationary? Surely the relative velocity of particle B in that frame it the overall relative velocity?

For particle B I set the velocity in the x-direction to be ##ucos60## and in the y-direction to be ##usin60##. I then just substituted those values into the equations for u'_x and u'_y. I obtained those values for u'_x and u'_y because both u_x and u_y are zero since the we are considering the...

Homework Statement In a given inertial frame two particles are shot out simultaneously from a given point with equal speeds u at an angle of 60 degrees with respect to each other. Using the concept of 4-velocity or otherwise, show that the relative speed of the particles is given by ##u_R =...