Final answer:
A microwave oven plate experiences nonzero tangential acceleration, centripetal acceleration, or both depending on its motion.
Step-by-step explanation:
When a microwave oven plate starts to spin, it experiences both nonzero tangential acceleration and centripetal acceleration. The tangential acceleration is responsible for the change in the plate's speed as it starts rotating, while the centripetal acceleration is responsible for keeping the plate moving in a circular path.
When the plate rotates at a constant angular velocity, it does not experience a tangential acceleration because its speed remains constant. However, it still experiences centripetal acceleration because it needs a force directed towards the center of the circular path to maintain its motion.
When the plate slows to a halt, it experiences a nonzero tangential acceleration directed opposite to its initial direction of motion. This acceleration gradually reduces the speed of the plate until it comes to a stop, and it also experiences centripetal acceleration until it stops rotating.