Variables in Experiments and Investigations Lower_02

The effect of the wind on Andrew’s fly ball is an example of a variable. Conditions can have a great effect on a player’s performance. Some stadiums are at high elevations. Mile High Stadium in Denver is at a high altitude. At a mile above sea level, the air is quite thin. The fewer air molecules the baseball collides with on its flight, the farther it can travel.

That’s great news for hitters like Andrew. Fortunately for pitchers, there are other stadiums that favor them over the hitters.

Boston has the Green Monster. It is a high wall in left field. This makes it more difficult to hit a ball over it. Some players have home stadiums where most of the games are played at night under lights. This variable may have an effect on how batters see the baseball. In baseball, like Science, there are many variables. Sometimes, but not always, scientists can control these variables.

During an experiment, scientists control variables. For instance, a scientist may test a new metal to find out how strong it is. In the image below, the nail is being tested for strength. In the experimental design, all the variables except for one must be controlled. The nail must be the same length. The hammer must strike the nail at the same angle every time.

The material the nail is going into must be the same for all tests. Even the temperature in the room can affect the amount the nail might bend. The only variable that will be changed, or manipulated, is the force with which the nail is hit. When the nail reaches its point of failure, it will bend. The amount of force needed to make this happens is the outcome variable.