When a mine cart goes over an activated rail the mine cart shakes and kicks out the player

When i was making a railroad I was trying to see how far the mine cart goes before I needed to use another activated rail. When I got into the mine cart and started to push myself on to the activated rail the mine cart began to shake and then kicked me out and just kept going. I then tried to pus the mine cart over a long string of activated rails and the mine cart just shook as it went across them and I attempted to get into the mine cart and it once again kicked me out.