It was the weekend, but Ned had work up to his ears, & it was driving him nuts. His brother dragged him out for some fresh air.
“C’mon, it’ll be fun!” Mike insisted. Ned grumbled.
They stopped at a nearby park. When they got out of the car, Ned spied a nearby tether ball. He edged moodily toward it, then out of nowhere punched the thing full force. The ball swung around the pole, smacking Ned in the back of the head & knocking him over in the process.
He got up, angrier than ever. “Think you’re funny, eh?” he growled, then punched the ball again. This time the ball flew straight into its pole, then bounced back to smack Ned in the face.
Mike turned to see what all the commotion was about; he was a bit startled to see Ned fighting a tether ball, & to his surprised amusment it looked like the tether ball was winning.
Wishing he had a video camera, he continued to watch & made a mental note to tell his physics students never to fight an inanimate object: because of Newton’s Third, the object always wins.