Hey all, I'm having a bit of trouble with this problem. Two events occur in an inertial system K at the same time but 4 km apart. What is the time difference measured in a system K' moving between these two events when the distance separation of the events is measured to be 5 km? I though I could use the length contraction equation to find the speed the frame is traveling and use that in the time dilation equation, but I don't know the proper time. I found the speed of frame K' to be 0.6c with respect to K. Thanks in advance for any help you guys give.