Foot–pound–second system of units

The foot-pound-second system of units is a way that people measure how big things are, how long they last, and how much energy they have. It's like playing with building blocks – we use different blocks to build different things, and we need to know how big the blocks are so we can figure out how many we need to use.

In this system, we use three different things to measure stuff. One thing is called a "foot," and it's like a really big ruler that we use to measure how long something is. Another thing is called a "pound," and it's like a block that we use to measure how heavy something is. The last thing is called a "second," and it's like a clock that we use to measure how long something lasts.

So, let's say you want to measure how tall someone is. You would use the foot-block to measure how many feet they are, like if they're 5 feet tall. Then, you would use the pound-block to put how heavy they are, like if they weighed 150 pounds. Lastly, you would use the second-block to see how fast they could run, like if they could run a mile in 10 minutes.

Overall, the foot-pound-second system helps us measure things in a simple and organized way, so we can understand and compare different things easily.