Back in 1998, on the job at [undisclosed car repair shop, as a tire tech], I spent a little idle time with one of the other guys in the parking lot.
We had decided to see whether a shop rag could be used as a sling.
Neither of us had ever used a sling before.
I loaded a D-cell battery, whipped the rag around like I've seen in movies, and released one end at just the right moment in its arc...
...and the battery sailed off in a lovely curve. I'd been aiming straight down the middle of the side parking lot, hoping to land the battery in the big field out back. Damn thing pulled to the right.
Then we realized that its trajectory had it sailing beautifully toward a parked van. A customer's van. Shiny, with lots of shiny glass windows. Expensive, job-losing glass windows.
WHACK!! It hit the parking lot retaining wall about 18 inches from the van, rebounded, and skittered along the pavement at the foot of the wall.
Enough excitement for one day.