Junior Engineer

Junior had just completed a course in statics and dynamics. He had learned that in equilibrium Sigma F (sum of all forces) = 0 and that F=MA, and armed with all his new knowledge got a summer job as an assistant to a building inspector on a construction project.

One evening after the workers had gone home, Junior found some bricks that should have been removed, up on the third floor. He decided that rather than bother the workers, he would remove them himself. The elevator shaft had a wooden barrel tied to a rope over a pulley suspended overhead. From the ground floor, Junior raised the barrel to the third floor landing and tied the rope at the ground floor level. He then climbed up, put all the bricks in the barrel, and returned to the ground floor. At this point, he forgot that in order for equilibrium to exist, Sigma F must equal zero. He untied the rope and, before he had time to think, he was 10 feet off the floor. He continued up the shaft as the barrel of bricks came down.

At the second floor, Junior and the barrel of bricks met. Considerable skin was scraped off and a few predictable exclamations issued forth. Junior continued up and the bricks went down.

Now, all this time, F = MA, and by the time the bricks reached the floor, the velocity was quite high. The acceleration, in a negative sense, was tremendous upon hitting the concrete floor. In fact, F = MA was so great that it knocked the bottom out of the wooden barrel.

Once again the forces were unbalanced, and Junior came back down the shaft. Once again they met in the middle, with more scraped skin and more flowery language, but this time F = MA was so high that Junior dropped the rope.

Once again the forces were unbalanced. The barrel fell down and hit Junior on the head.

Junior wrote to his accident insurance company citing four accidents: One going up, one coming down, one when he hit the bricks, and one when the barrel hit him.