Minecraft wiki entry for Redstone_components, associated text: The player can move a minecart by pushing against it while outside the minecart (whether the minecart is on rails or not), or by pressing the Forward control key (by default, W) while inside the minecart (only while the minecart is on rails). A minecart resting on powered rails configured to point at an adjacent opaque block is propelled away from the opaque block when the powered rails are activated. A minecart traveling over activated powered rails gets a speed boost. When a minecart passes over an activated activator rails, the entity inside it is ejected out.