Rover grabs the tablecloth and starts backing away from the table at 20 cm/s. a glass near the other end of the tablecloth moves toward the edge and finally falls off. the table is 80 cm high, rovers mouth is 10 cm above the floor, and 200 cm of tablecloth separates rover’s mouth from the glass. at the instant the glass reached the table’s edge, was it going faster or slower than rover’s 20 cm/s? by how much?