In a very busy off-campus eatery one chef sends a 217-g broccoli-tomato-pickle-onion-mushroom pizza sliding down the counter from left to right at 1.67 m/s. Almost simultaneously, the other chef launches a 327-g veggieburger-on-a-bun (with everything, but hold the horseradish) along the same counter from right to left at 2.27 m/s. The two delicacies collide head on at the given speeds-the counter is practically friction-free due to accumulated grease-and merge into a single, unbelievably savory serving. At what speed does it move? Enter a positive number.