A frictionless ramp is constructed so that it is at a 30 degree angle to the horizontal. It is 3.2 meters long and 1.6 meters high. A 3.0 kg block is released at the top of the ramp and slides down onto a frictionless horizontal surface where it hits and sticks to another block that has a mass of 7.0 kg. After the blocks travel some distance, the blocks come to a rough patch that has a coefficient of friction of 0.25 between the blocks and the rough surface. How far along the rough patch do the blocks go before stopping?