What happens if with quantum entanglement u take one particle at a near light speed?

Nothing more unusual than normal entanglement studies.

Say you made two entangled electrons that spat of in two directions. One electron is accelerated and the other slowed and held in an electron trap (which would be very difficult to do without breaking the entanglement but lets ignore that). Then no matter now far away or fast the 1st electron went, when you measure the trapped one the 1st would instantly change it's "properties" due to the measurement.

People normally test entanglement by firing entangled photons (which travel at the speed of light) apart. When they are  a big distance apart they measure one photon and see how quickly the other is affected. So far all measurements have shown that the other photon is affected instantly.

In short the other particle knows it's "entangled brother" has been measured despite the fact that no information could have been exchanged. We known this as informations can only travel at the speed of light not instantly.

Interesting isn't it.